I know it's not a stompbox so I'm sorry if this is irrelevant to the forum or if no one can relate to such a project.
I've edited this post after a night of long research. I've also noticed I've started a similar topic about a year ago that went absolutely nowhere. So if you've decided to check this one out I'm very grateful!
I was trying to figure out what tubes (from smallbear) would be good for a Superfly build. I eventually found an answer and have decided to make a few ebay purchases in the daze of midnight -last night :icon_rolleyes:
So I have 2 packages coming in by the end of the month. A 10 pack of each - 6n16b and 6n17b which has been used in at least one successful Superfly Special build and are also a good choice according to information on THIS SITE ON SUBMINI TUBE SIMULATIONS (http://www.dmitrynizh.com/submini-vibro-reverb.htm) Plus they're so much cheaper than tubes closer to home. I've also ordered a couple 6111W tubes if a higher voltage tube becomes ideal at the power section.
I'm still a noob... So I'm asking anyone reading who may have ideas to please review the link above and explain how one would connect a reverb tank and also explain the second (reverb) transformer in the schematics. Is it still part of the main transformer? (125A will be the case) I'd like to start by breadboarding the Superfly and then adding reverb. From there I'll mold it into a submini fender amp.
Here's the Superfly Special page if you've been missing out!
LINK (http://www.diystompboxes.com/smfforum/index.php?topic=78302.120)
I've updated the above post. I hope someone is interested enough to comment or explain.
Rock on, guys. 8)
Way way way above my paygrade but good luck Kevin.
Typically your reverb transformer is going to be an additional unit, not part of your output transformer. You cannot isolate windings for two different purposes in your output tranny; the signals would interfere with each other and do bad things. Also, I don't think the impedances would match well anyway.
Quote from: Ripthorn on May 04, 2016, 12:17:40 PM
Typically your reverb transformer is going to be an additional unit, not part of your output transformer. You cannot isolate windings for two different purposes in your output tranny; the signals would interfere with each other and do bad things. Also, I don't think the impedances would match well anyway.
Thank you for replying and clearing that up! Here's a quote on the power input of these transformers
QuoteThe 230V B+ of the output stage can be combined with the 190V B+ of the reverb stage; on my prototypes these were fed from separate PS units and the two show up on the schematics
This is where I thought it was one of the same transformer. Though it is getting less power... I'm still confused. Any suggestions on a reverb transformer? Man... the bill only gets bigger... I wish the author of that page noted ideal transformer specs...
I was also confused on the power supplies for some of the schematics on that page. But now as I understand - there's 4-5 individual power supplies (rather, 4-5 appropriate voltages) in two of the push-pull circuits.
I'm going to be buried in research for a while. Keep the info coming!
As I recall, the 125A is an output transformer. The voltage needed by both the OT and RT can indeed be supplied by the PT, but you will need to make sure you get the appropriate B+ on each.
Quote from: Ripthorn on May 04, 2016, 12:51:59 PM
As I recall, the 125A is an output transformer. The voltage needed by both the OT and RT can indeed be supplied by the PT, but you will need to make sure you get the appropriate B+ on each.
Of course! So if they can share the transformer could you or anyone who understands mark the pins of the trasformer in junction to the 125A schematic? It will certainly help me wrap my head around the schematic and some of it's workings.
(https://dl.dropboxusercontent.com/u/91866359/125Aschm.png)(https://dl.dropboxusercontent.com/u/91866359/tnsfschm.png)
I've only worked with small transformers for octave-fuzz effects.
If you look at the first three schematics you'll notice a "AC voltage source, (~)" symbol. I've never seen one before. My guess would be a fuse but I know nothing about this. Could someone elaborate on what this is? For what reason is it not in the last schematic with the Russian tubes?
Your question is still a little vague, but here is an answer based on what I understand of your question:
After you rectify your AC and filter it, you have B+1, B+2, etc. B+1 goes to the center tap of the primary side of your 125A. You would need a separate B+, let's call it B+R for your reverb, that will be further filtered and will be lower voltage than B+1. B+R will be fed to the one side of your reverb transformers primary, while the other primary is connected to the reverb tube's plate. There is no direct connection between the 125A and the reverb transformer. Your amp will have a total of 3 transformers: power, reverb, and output.
The little squiggly symbol is usually a fuse.
The reverb transformer is used as the output transformer! It happens to be a convenient transformer for this design. There is NO reverb tank in the design.
My apologies. I misunderstood. So I would indeed need a second transformer (one that isn't center tapped) for the reverb. The main power would be via SMPS as the Superfly is setup on.
If you could, please suggest a transformer that would be appropriate so I'm on the right track. Obviously it would have to take up to 190 volts on it's top primary connection (pin1?). I believe that another 125A would work just as well. But I'd rather find something better on my wallet for this one if possible...
Thank you for taking the time to answer my questions, Ripthorn. I really appreciate it.
Quote from: tonyharker on May 04, 2016, 02:13:25 PM
The reverb transformer is used as the output transformer! It happens to be a convenient transformer for this design. There is NO reverb tank in the design.
Wait, what? I thought that's what the E1 tank in the schematics were... Please explain.
How many transformers do I actually need w/ use of reverb? :o
I see you viewing, thomasha!
Come on in! Help me understand if you could ::)
Your work on the Russian Superfly has fueled my ambitions!
Hehe,
I was going to start posting my videos...
I think there is some confusion about which schematic you're using!
let me post this here>
(http://www.dmitrynizh.com/6n17b-6n16b-vibro-reverb.gif)
Yes that is the most relevant one. I think it's based off the Murder One with tremolo and reverb added (my guess). Sure does resemble the Superfly in parts.
I made a layout for this one (kind of, was a layout that could be used both for the superfly as for this one).
The feedback to the grid of the second triode didn't impress me, so I built a modified superfly in the end. The problem with my layout was noise near the first stage, and after that one I decide that it is easier to build the SMPS in a separate board and move it to a position that produces less noise.
back to your schematic, with the currents its easy to calculate the resistor between the high voltage stages. So you only need one HV source.
You're right about the reverb, it's quite a small SE amp inside the amp, with the signal modified by the springs that goes back and is mixed with the rest of the signal. So you will need the Hammond 125A PP transformer, the 3W version is OK, for the output stage, that goes connected to the speaker and the fender reverb transformer with 22,5k also called 22921 for the reverb.
I saw that you're thnking about the SMPS thing, but with the small amplifier and the reverb, I would expect a lot of heat, and your 12V wall wart would be > (4 tubes with 400 mA heaters, in series& parallel would need 800mA, and the SMPS with 230V 20mA with an efficiency of 70% would require more 600mA, 1400mA total, I would use my 2A one).
I'm guessing the current here, I modified the cathode resistor in my build and it is higher. While my superfly has no problem with heating, my jcm combo has...
Cheers,
Thomas
Quote from: thomasha on May 04, 2016, 03:12:47 PMthe fender reverb transformer with 22,5k also called 22921 for the reverb.
Woah there we go! Thank you kindly. At about $20 that's not so bad. Perhaps I can find something similar for less on mouser.
EDIT: Just noticed; that reverb transformer "22921" is the main transformer in the Murder One project.
Great suggestions! Keeping everything in mind for sure.
When your $60 amp idea is tossed out the window... Can't wait to start!
Happy DIYing! :icon_biggrin:
All this talk about reverb transformers...
We need a layout for a Sub Mini Tube Reverb amp.
Using one of those small reverb tanks...ie: https://www.tubesandmore.com/products/P-RAMC2BF3
Unfortunately I don't know enough about tubes etc. to do it myself.
But would be neat.
this one is a good one too>
https://www.tubesandmore.com/products/P-TF22921 (https://www.tubesandmore.com/products/P-TF22921) for 14 bucks
and for the output stage you could use a 5w 100v line transformer, it's really cheap when compared to the 125a.
Quote from: thomasha on May 04, 2016, 03:48:09 PM
this one is a good one too>
https://www.tubesandmore.com/products/P-TF22921 (https://www.tubesandmore.com/products/P-TF22921) for 14 bucks
and for the output stage you could use a 5w 100v line transformer, it's really cheap when compared to the 125a.
Sweet deal! Any suggestions on a particular output transformer with those specs? Looking into it myself I keep looking at more Hammonds... I'm not sure what you mean "100v line" as you put it. I know I'll need something that can handle up to 200 volts but I'm not sure what specs I should be looking at.
I'm obviously misunderstanding something :icon_rolleyes:
This> http://www.altronics.com.au/p/m1112-8-ohm-to-0.33w-5w-pa-speaker-transformer/ (http://www.altronics.com.au/p/m1112-8-ohm-to-0.33w-5w-pa-speaker-transformer/)
It's also known as PA transformer or 100v line matching transformer, there is also the 70v version, more common in the US that also works.
some theory > http://www.ozvalveamps.org/optrans.htm (http://www.ozvalveamps.org/optrans.htm)
http://home.alphalink.com.au/~cambie/6AN8amp/6an8amp.htm (http://home.alphalink.com.au/~cambie/6AN8amp/6an8amp.htm)
and here:
http://www.diystompboxes.com/smfforum/index.php?topic=52385.0 (http://www.diystompboxes.com/smfforum/index.php?topic=52385.0)
and almost forgot the right connections! http://www.diystompboxes.com/smfforum/index.php?topic=52385.0 (http://www.diystompboxes.com/smfforum/index.php?topic=52385.0)
It's cheaper, but only works for PP because there's no gap, in SE there would be saturation...
I think that it is a good when I can't find the 125A transformer at a good price.
Great links! I actually recognize a couple from when I was researching last year. It's all a fuzz :icon_cry:
Great info on transformers. I will not be tampering with them (seen some transformer mods/tweaks)
I can't believe I missed this one. It's half the price of the 125A, for a Fender power amp and in stock on mouser.
Hammond 1750A (http://www.mouser.com/ProductDetail/Hammond-Manufacturing/1750A/?qs=sGAEpiMZZMv0IfuNuy2LUU8FmnYGIyK2AOwYSBEK47I%3d)
EDIT: Oops. Just realized it's the reverb tank transformer...
They also have the 1750H which is the Fender Reverb Amp transformer though it's 20watts - for the same price as the 125A.
Must not give in...
Okay...
On amazon of all places I found "OSD Audio SP70T 70-Volt Commercial Line-Matching Transformer (http://www.amazon.com/OSD-Audio-SP70T-Line-Matching-Transformer/dp/B007TJNP5M?ie=UTF8&psc=1&redirect=true&ref_=ox_sc_act_title_1&smid=ATVPDKIKX0DER)" for $15USD!
(https://dl.dropboxusercontent.com/u/91866359/transfmer.png)
Is this the American version of the Transformer you were talking about? Or will it work just as well?
Wouldn't it also work as a reverb transformer if I don't use the center tap?
Also... If I'll be giving it upwards to 200 volts from the SMPS wouldn't that be an issue? This is what I'm not understanding right now.
I apologize if my constant updating bothers anyone. I've been trying to wrap my head around tube amp topology and transformers all day.
Though those links have great information I don't understand how it all works even though I just read through everything! As I said I'm a noob :'(
I do however understand that people have claimed to have successfully applied these 70-100volt power transformers as output transformers. If I can get away with using a $5 transformer of course I'll try! I've found this as well;
"70V 15W Speaker Line Matching Transformer (http://www.parts-express.com/70v-15w-speaker-line-matching-transformer--300-039)" under $5!
There's also a 10w one that also has a 5w lead - for even less $
My concerns are if I would have to modify the transformer or if it becomes more trouble than it's worth to an amateur stompbox guy like myself. And also nothing (especially audio quality) is being greatly compromised.
Is this something that you have tried yourself? Most output transformers are described as "tube output push pull". The links you have shared suggest there wouldn't be implications using one of these 70volt line matching transformers as a substitute for such a tube amp project if I understand correctly.
EDIT: I found this looking into using this as the reverb transformers and found great information. I say it's well worth a shot for the output and even the reverb transformer. People have reported have success in either possition! I can't see why not both. But of course there's likely many variables to consider.
Ehh I put up the wrong link. Will fix later.
There's allot of information about the workings of a transformer and it's roll in an amp as well as using these cheap transformers for a push-pull circuit. Seems promising and worth a shot - saving a large chunk of dough.
Ahhh now it's coming together.
Nice that you found cheaper versions!
on the other side of the atlantic the hammonds are really expensive and this line transformers are a good option for push pull output stages.
As for the reverb, there is always the problem that the reverb requires a SE transformer, that needs an air gap to avoid saturation. I haven't used one of this line transformers, but I used a 220v to 6v transformer with good results, even in SE, but I haven't measured the frequency response of it. The thing is, some guys open the transformer and change the lamination arrangement. I tried amps with this rearrangement and without it and it's hard to identify some difference in tone, but when using a good SE transformer the difference is huge.
Just one thing, I like the 5w transformers because they're smaller (the 125a is still smaller but the price...) and all my builds are mostly in small pedal enclosures or mini combos.
I think the fender reverb from the link that I sent you is really small and there are some equivalent versions that are cheaper, you just need to look at tubesandmore, mojotone, angela and the other amp stores and search for a 22.5K primary to 8 ohms or 11.5k to 4 ohms and it will work.
just in case you are passing a jaycar ....
http://www.jaycar.com.au/Power-Products-Electrical/Power-Conversion-%26-Transformation/AC-AC-Transformers/5W-Line-Speaker-Transformer/p/MM1900
If you have a 70.7 volt transformer, the 1 watt setting gives you a 5 Kohm impedance, 2 watts gives you 2.5 Kohm etc. The 5 watt tap gives you a 1 Kohm impedance and most tubes, even most triodes, require more than that. Line transformers are cheap and plentiful, so I have used them in a number of projects of my own.
Make sure if you are using the transformer in a push-pull output that you have the necessary two windings with the correct voltage split. I have a Burtek T7010C transformer with 0.625, 1.25 and 2.5 watt taps to the common ground. The resistance from common to the 0.625 is 339 ohms, to the 1.25 is 211 ohms and to the 2.5 is 88 ohms. The inner windings will of course have fewer ohms than outer windings, so you cannot get a guaranteed even resistance split and in a matching transformer, no one cares.
To run a balanced push-pull output, you need one tap with four times the power rating of another. There is a common lead and tap leads. The common lead is going to be one of the plate leads. For the Burtek T7010C, one plate goes to the common, another goes to the 0.625 and the centre tap is the 2.5 (verified by voltage measurements using an oscillator). This gives 2 K from plate to centre tap or 8K plate-to-plate, a very usable impedance, but not a very high wattage. It is essential to have one tap at four times the wattage of another tap to get balanced push-pull operation. You have that with the #300-039 transformer you have described but the 5 and 20 watt terminals give you 250 ohms on each side or 1 Kohms plate-to-plate. This is very low for most tubes. Even with the Burtek, you don't get the balanced resistances you would have with a transformer designed to be an output transformer.
I have used a number of these transformers with old (1920's) radios with a single-ended triode output and I even built a box with a transformer and a rotary selector switch to select impedances. The DC current through battery tubes is too low to cause saturation, but for a power output, pay attention to the wattage ratings even when you are running push-pull.
Thank you so much for that information, amptramp.
I was just about to ask what wires I should use in respect to the superfly schematic. I was wondering what wire would be the choice for the primary's top lead and center tap.
This is a wire diagram of a 10watt 70volt transformer I will use for the push pull output.
(https://dl.dropboxusercontent.com/u/91866359/tnsfschm.png)
Let's see if I got the wiring correct for the Superfly Special schematic with this transformer using the 5w lead...
Primary: 1.25w to the top tube's plate, .5w/5w is center tap and C to the bottom tube's plate.
Secondary: 8 ohms to speaker, C to ground
Everything not mentioned should be left unconnected.
I'm assuming here it wouldn't be a problem using a 10watt or 15watt transformer as long as the 5watt and 1.25watt wires are available (since I'll be using 5watts). Is this correct? I likely snag a smaller 5watt max one in the future - if I can ever find them.
im trying to work my way up to tube amps as well starting with sub-mini tubes ..I have the 5672 pretty well mastered but its only 5 nodes and too similar to a bjt so it was easy ..a triode is another beast it seems
I am following this thread with great interest ..and yes , we need a working layout, a place for us noobs to begin .
I have the fender 022921..which is slightly different than the 125A but exactly like the 1750a
and my speaker is reading closer to 12 ohms than 8 ohms ..and its a new 30 dollar 12" ..not sure how much the load affects the circuit between 2.4.8.16 ohms speakers
I just paid about $4 for the transformer I'll be experimenting with. A 125A is about $40 where I can find them so I'm very stoked to try this alternative.
I have also ordered a pair of 4 ohm 6.5inch Eminence speakers for ~$12 each! Submini twin reverb/tremolo blues amp... here I come 8)
Quote from: LightSoundGeometry on May 05, 2016, 02:06:09 PMI am following this thread with great interest ..and yes , we need a working layout, a place for us noobs to begin .
I've been putting great effort into translating these kind of projects to a language I can understand (or rather, learn a few foreign words). Break 'em down bit by bit till I can wrap my head around them. I do hope to have information to share with amateurs such as you and I so we can work on such projects comfortably. A hell of a transition from a stompbox though - I'm coming from no electrical background other than a couple years hanging around this forum and building and tweaking stompbox clones.
Quote from: Kevin Mitchell on May 05, 2016, 02:21:15 PM
I just paid about $4 for the transformer I'll be experimenting with. A 125A is about $40 where I can find them so I'm very stoked to try this alternative.
I have also ordered a pair of 4 ohm 6.5inch Eminence speakers for ~$12 each! Submini twin reverb/tremolo blues amp... here I come 8)
Quote from: LightSoundGeometry on May 05, 2016, 02:06:09 PMI am following this thread with great interest ..and yes , we need a working layout, a place for us noobs to begin .
I've been putting great effort into translating these kind of projects to a language I can understand (or rather, learn a few foreign words). Break 'em down bit by bit till I can wrap my head around them. I do hope to have information to share with amateurs such as you and I so we can work on such projects comfortably. A hell of a transition from a stompbox though - I'm coming from no electrical background other than a couple years hanging around this forum and building and tweaking stompbox clones.
my goal was never pedals ..it was always tube amplifiers from day one. yes one hell of a transition ..the thing is there is no school that teaches this stuff .. you tube videos come the closest but they never get into any real detail on how to ..more of look at me and what I did ..Im not really book smart enough to follow along but am trying ..wish I had a real life mentor to pass along the skill to me..I need guidance and instruction , cant do this all on my own from some pdf files online ..
I am in school right now but I think school is now watered down and they dont really teach much anymore like they used to ..its a degree factory for funding ..its purely a business and the lower standards bring in larger numbers = more funding ....they could care less what you learn and what is taught ..all about keeping classes full for money.
my temper, I think I may need to let it go for a little bit and come back to it ...im scared of burning down my house..I had an awful smell the other day..scared something may turn into an uncontrollable fire
What I wanted in the beginning was to build a mini-moog clone. But I had nowhere to start. I'm a guitar player who absolutely loves to play with keys and synths. I get lost in playing with those much easier than with guitar.
I'm with you on the education stance. I want to go to a trade school to get certified and learn the basics but I will certainly not get all that I want out of it. But it would be nice to understand the language. I would absolute love to be an apprentice for an electical/audio engineer. (pull my name Roger Mayer or Bob Moog!) lol ;) I often dream of being a tech roady.
You best keep an extinguisher at the ready. Only strange smell I've had was from what R.G. Keen calls an LEP I think "light emitting pot" Something on breadboard wasn't right and a pot as a voltage divider started to light up and smoke!
There's my rant lol. I need someone to prove my explanations on the 10watt transformer connections above.
Quote from: Kevin Mitchell on May 05, 2016, 03:20:08 PM
What I wanted in the beginning was to build a mini-moog clone. But I had nowhere to start. I'm a guitar player who absolutely loves to play with keys and synths. I get lost in playing with those much easier than with guitar.
I'm with you on the education stance. I want to go to a trade school to get certified and learn the basics but I will certainly not get all that I want out of it. But it would be nice to understand the language. I would absolute love to be an apprentice for an electical/audio engineer. (pull my name Roger Mayer or Bob Moog!) lol ;) I often dream of being a tech roady.
You best keep an extinguisher at the ready. Only strange smell I've had was from what R.G. Keen calls an LEP I think "light emitting pot" Something on breadboard wasn't right and a pot as a voltage divider started to light up and smoke!
There's my rant lol. I need someone to prove my explanations on the 10watt transformer connections above.
Paul in the Lab has a 5 watt amp using an opamp ..reviews says it pushes a 1x12pretty good ..cam across this searchign for something else. I think i might give it a go, he has a stripboard layout.
http://www.paulinthelab.com/2013/02/sparky-5-watt-amplifier-stripboard.html
Thought Paul was a colleague or something till I clicked on the link :icon_lol:. I've used simple 386 (LM, JRC) circuits to amplify synth stuff on breadboard and guitar on a few occasions. I might try Paul's circuit when I need it! Sounds super clean. Though it's not a tube amp. Gotta have that mojo. Well... I do :icon_biggrin:
QuoteI need someone to prove my explanations on the 10watt transformer connections above.
I made some calculations for 70v and a 8 ohms speaker and ended up with this:
Zs Tap
0 0 common
490 10
980 5
1960 2.5
3920 1.25
7903 0.62
One side must have 4 times the impedance, so i guess 2.5 would be the center tap, 0.62 and common for anodes;
the math can be found here>http://home.alphalink.com.au/~cambie/6AN8amp/M1115.htm (http://home.alphalink.com.au/~cambie/6AN8amp/M1115.htm)
Quote from: LightSoundGeometry on May 05, 2016, 02:06:09 PM
im trying to work my way up to tube amps as well starting with sub-mini tubes ..I have the 5672 pretty well mastered but its only 5 nodes and too similar to a bjt so it was easy ..a triode is another beast it seems
I am following this thread with great interest ..and yes , we need a working layout, a place for us noobs to begin .
I have the fender 022921..which is slightly different than the 125A but exactly like the 1750a
and my speaker is reading closer to 12 ohms than 8 ohms ..and its a new 30 dollar 12" ..not sure how much the load affects the circuit between 2.4.8.16 ohms speakers
I'm not familiar with the 5672, but triodes are the simplest type of audio tubes. Like a BJT with a heater, basically. Plate (anode)=collector, cathode=emitter, control grid=base. Anything less and you have a diode/rectifier.
If your speaker measures 12 ohms resistance, it is a 16 ohm (impedence) speaker. You can use it in place of an 8 ohm, and nothing will be harmed. You will lose a bit of volume from the impedence mismatch. With a cheap speaker, you may lose much more volume due to low effeciency.
Quote from: Kevin Mitchell on May 05, 2016, 05:54:54 PM
Thought Paul was a colleague or something till I clicked on the link :icon_lol:. I've used simple 386 (LM, JRC) circuits to amplify synth stuff on breadboard and guitar on a few occasions. I might try Paul's circuit when I need it! Sounds super clean. Though it's not a tube amp. Gotta have that mojo. Well... I do :icon_biggrin:
no, I feel you, MOJO WORKS ..I gotta have it myself ..even 600 volt orange dips and 10 dollar crystal diodes 8)
http://www.ebay.com/itm/1N39A-germanium-diodes-five-5-Vintage-Sylvania-very-rare-crystal-radio-/121940041538?
trust me , the pentode tube is the easiest ..almost too simple its not a good jumping board lol ..its helping though identify stuff etc.I guess it was okay, its teaching me two sources and have to watch I and E both ..learning the nomenclature etc
https://frank.pocnet.net/sheets/138/5/5672.pdf
------------------------
what kind of synth is he using in Frankenstein ? I always thought it ws some dude jamming out on a super moog
dude is rocken the synth lol
Quote from: Kevin Mitchell on May 05, 2016, 03:20:08 PM
(pull my name Roger Mayer or Bob Moog!)
Bob Moog is dead. Just sayin'.
here we go ..will modify post as I go
(http://s32.postimg.org/m24zvs69x/IMG_0977.jpg)
b+ charge pump
(http://s32.postimg.org/l5gy5voat/IMG_0978.jpg)
about halfway through, decided to kick on power.. firey burn smell and tube lit up but I shut down quick ..does the tube itself maybe stink a little when it gets hot?
(http://s32.postimg.org/epsh1h805/Full_Size_Render_6.jpg)
well it kicked on but wasnt real loud or sound particularly good ..its the 2 watt 18ohm resistor heating up and the tube smelling like fire/burning plastic
(http://s32.postimg.org/jna4zdhz9/Full_Size_Render_7.jpg)
(http://s32.postimg.org/cuwagft51/Full_Size_Render_8.jpg)
I dont even want to mess with this thing anymore ..that smell...I was hurt 16 years ago in a work accident so I get nervous really easy but it was stankin good and very, very, very hot
the tubes get really hot, you could easily burn your fingers.
My amp smells too, maybe it's the resistor, or maybe the tube, or both, if you think the resistor is too hot, you could use one with higher wattage or use two in parallel, same wattage, but double the resistance.
The 5672 has almost no glow, while the 6111 glows like hell, that's normal.
The sound is not very loud, and with a low efficiency speaker it will be even lower, so you can easily play after minight.
With a celestion 1x12 it's too loud for late night practice.
This amp should be very safe if you're using the right wattage resistor for the heaters. I burned like 3 of the IC's just by shorting the high voltage, so before you could start a fire it would burn the IC.
If you're afraid you should stop, or at least build the PCB version. With everything soldered it is much safer, and there are no crazy wires moving around.
if you get game enough to start it up again, measure the voltage across the 18R resistor, from end to end (it doesn't connect to ground, does it?)
then do ohm's law - P=V*V*R - and tell us what you get.
Are you guys playing around with the MAXX1044 charge pump? I'm planning to use the SMPS stetup with the 555. Perhaps I'll experience less fumes...
Oh I've noticed you're using a 5672. I'm sticking with 6n17B and for the power 6n16B or 6111WA.
I don't want to throw discussions off too much but I have a heap of LT1072 DATA SHEET (http://cds.linear.com/docs/en/datasheet/1072fc.pdf) "1.25A High Efficiency Switching Regulator". I'm curious to see if it would be of any use here. Bull I'll be sure to get the SMPS down first. I'll probably place a mouser order tonight. Then all I'm missing is a reverb tank. Everything else should be on the way.
A couple of 6111WA tubes came in yesterday. They're very slim and as tall as my pinky-tip! :o
Here's a concept of where I'll start off;
(https://dl.dropboxusercontent.com/u/91866359/FenderTR%20Tone%20Stack.png)
Ignore the second tubes connection :icon_lol: They're not wired right. I'm still working out the feedback (resonance) section also but that's for later down the road.
It has a simple fender tone stack and uncompleted for the sake of testing and adding a reverb circuit.
Quick question if anyone could answer it;
I'm thinking it may be a problem if I were to use a 12volt 500ma PSU to the SMPS - possibly being not enough current to drive 4+ tubes as I would eventually be doing.
So I'd likely have to modify the SMPS and upgrade my wall wart :icon_cry:
Any validation or suggestions would be super. Thanks guys.
Quote from: duck_arse on May 07, 2016, 11:08:35 AM
if you get game enough to start it up again, measure the voltage across the 18R resistor, from end to end (it doesn't connect to ground, does it?)
then do ohm's law - P=V*V*R - and tell us what you get.
Sure about this? P=V*I=V*V/R
four russian tubes in series parallel at 12V each pair will need at least 800mA. The SMPS will draw a little less.
I use a 2A 12v Wall wart, and you can find some cheap ones. For my superfly, with only 2 tubes I use a 12v 1A switched wall wart.
Quote from: thomasha on May 09, 2016, 01:56:16 PM
four russian tubes in series parallel at 12V each pair will need at least 800mA. The SMPS will draw a little less.
I use a 2A 12v Wall wart, and you can find some cheap ones. For my superfly, with only 2 tubes I use a 12v 1A switched wall wart.
Yes I've noticed. I actually paused your submini marshall video to read the specs on the adapter :icon_lol:
So the adapter I have now may not even drive 2 russian tubes :-\
The first Superfly used a 12volt 500ma adapter for 6112/7327 pair I believe. This makes me skeptical on what the current draw of my setup will be. But hey I'll give it a shot when I'm only running 2 tubes.
I solved my PSU issues by ordering some PTs from the local transformer shop. This way you have a real power supply, not some crappy SMPS. I used SMPS in some tube pedals but for an amp I prefer the good old PT.
(http://i7.photobucket.com/albums/y263/GreggPics/SubminiTop.jpg)
Thanks, MetalGuy.
Since I'm building a small amp head and very likely not using an encosure it may be ideal to use a power transformer in my case. Though I'm a bit nervous about messing with line voltages. I have no experience with transformer outside of octave fuzz pedals.
Could you please share some ideal specs for a PT for my case? I can't special order any parts here... So purchasing from an online US vendor is ideal for myself. I'm also making this a budget build. Or at least I'm trying :icon_lol: I would like a PT that could work for the superfly on breadboard and also not be a problem as I go on adding to and modifying the circuit. Likely a 6 tube minimum project. So I'd have to take in consideration the current needed - increasing by ~300-400ma for each tube I add if I understand correctly.
I could recommend you many options but mainly from an european vendor with local primary voltages. They have an US version as well but it's the only one:
http://www.tube-town.net/ttstore/Transformer/Power-Transformer/Toroidal/Toroidal-30VA-US-Version::6842.html
This will be enough for max of 5 tubes though.
Thanks for the timely reply! I was meaning to mention I have a "120" transformer from a Frontman 15G and I'm unsure if it would be of any use here. I can't find a datasheet on the transformer but here's the amp's schematic (http://support.fender.com/schematics/guitar_amplifiers/Frontman_15G_15R_schematic.pdf) with some details "+16, 0, -16". My guess is not good or not good enough.
I'm trying to wrap my head around PT specs for what I would need. I'm clueless on this topic.
As far as US suppliers for power transformers, Antek has a large selection of transformers that would work well:
http://www.antekinc.com/
Depending on your tube complement of course. You might find them to be a bit large compared to the size of the amp you want to build though. For an amp using only preamp tubes I would lean toward a 2A 12v wall adapter and MAX1771 SMPS like Thomasha's mini jcm800, but I'm obsessed with miniaturizing things so that's just me.
Thank you very much! The SMPS is within my comfort zone though I'm trying to be practical here. I suppose it wouldn't hurt to build the 555 SMSP or perhaps even the MAX1771 version and see how far it can go. As I've mentioned I'll eventually need enough current to run 6 tubes at the least.
Quote from: MetalGuy on May 09, 2016, 03:55:24 PM
I solved my PSU issues by ordering some PTs from the local transformer shop. This way you have a real power supply, not some crappy SMPS. I used SMPS in some tube pedals but for an amp I prefer the good old PT.
(http://i7.photobucket.com/albums/y263/GreggPics/SubminiTop.jpg)
iron and tube :icon_exclaim:
Okay... I've been absorbing info on power transformers and using submini tubes.
From what I've gathered I know I'd need a power transformer that pushes ~200v and also has a 6.3v filament connection with as much as 3-4 amps (400ma per tube) for the heaters - may that connection come as a dual secondary.
It's difficult sourcing a PT in the US that fits the bill and wont break the bank... But I'm taking my time and learning allot - appose to learning along the way as I have been. There's so much more to dig up before anything starts to look like an amp... I also should stock up on a variety of higher wattage resistors considering the current consumption on the heaters and anodes -res. to B+ - if I'm not mistaken. I thought my 12v 500ma adapter would suffice to experiment a little but sadly not without halfing the voltage with better resistors for the heaters (need more current and 1/4 watt wont be enough) I was actually expecting the 1/4 watt to burn up but that didn't happen. Nothing happened.
I would like to put together a test build using one or so of the russian tubes for an overdrive or distortion running at low voltage. This will be an actual effects pedal. After developing a nice preamp I can experiment with higher voltages and eventually throw on an output section and the reverb thus creating a legitimate submini tube amp.
This project is on-going and very much open for discussion. I have much more to learn. Still wrapping my head around what I just wrote here :icon_lol:
QuoteI thought my 12v 500ma adapter would suffice to experiment a little but sadly not without halfing the voltage with better resistors for the heaters (need more current and 1/4 watt wont be enough)...
If you're going to experiment you can connect 2 tubes' heaters in series (a 12v 500ma adapter will be good only for that). This way your voltage issues are automatically solved.
Thanks, man! That's something I didn't consider. I checked that out last night and the two tubes glow nicely reading 6v with .4A draw between them.
(https://dl.dropboxusercontent.com/u/91866359/IMAG0197.jpg)
If I have time this weekend I'd like to breadboard a tube-vibe. I guess I'd use the two tubes for the phase stages and a nontube buffer since it's unlikely I could use more than 2 tubes with the 12v 500ma adapter though I'm unsure to how much current would be left to work with. Since the heaters have a minimum rating of 5.7 @ .4A I don't think there's any tricks I could pull here without gathering more parts and an appropriate transformer/wallwart.
I forgot to drop this in;
Vintage Vibe" Low Voltage 6111 Submini Tube Vibrato (http://www.diystompboxes.com/smfforum/index.php?topic=74262.0) - You're the man, frequencycentral!
This inspired me to work up submini tube effects pedals. So I'm going to do a tube-vibe!
Thought I'd check in. It's been a few months and I've been between a few projects absorbing the experience. I grow stronger with every 230v zap.... I've got a 555 SMPS working smoothly. Though I may source a power transformer once I work out the chassis and speaker spacing.
Tonight a reverb tank + transformer came in. I've added it to a Superfly-like circuit I've had on breadboard and it works okay at the moment. The amp is way too gritty and all the controls seem to react with each other. Not too pleased with that. I have to fine tune allot of things and pretty much rework the entire circuit - while also aiming for it to resemble a Deluxe Revert amp.
The output transformer I've chosen works alright. I may find a better one for more power. I've got some 6P30B tubes on the way hoping that using those output pentodes improve the output level and clarity.
So for now I'll be cleaning it up, adding a fender tone stack and then work on the vibrato. It's finally coming together :icon_biggrin:
Nice update!
It looks like this will be an awesome small tube amp with reverb an all.
hoping to see how it turns out.
Quote from: Kevin Mitchell on May 05, 2016, 03:20:08 PM
What I wanted in the beginning was to build a mini-moog clone. But I had nowhere to start. I'm a guitar player who absolutely loves to play with keys and synths. I get lost in playing with those much easier than with guitar.
I'm still alive and kicking. In case anyone was curious :icon_rolleyes:
I'm posting here because I knew I've mentioned my DIY goals somewhere on the site. Though I do not yet have a finished submini amp, I have went the extra mile and built a deluxe reverb from scratch. Here are some photos taken a while back when I was finishing it up.
(https://image.ibb.co/hqPCh6/FB_IMG_1513879919345.jpg)
(https://image.ibb.co/bx0UUm/FB_IMG_1513879922982.jpg)
And for my recent endovour... Minimoog clone - eurorack format designed by Guinguin Instruments.
(https://image.ibb.co/ns63pm/20171121_082159.jpg)
Happy holidays everyone.
-KM
Anybody looking for an alternative for a power supply transformer if you don't have the option of something cheaper. Hammond 229C12.
https://mouser.com/productdetail/hammond-manufacturing/229c12?qs=sGAEpiMZZMvwUzoUXIIvyQPvPmwnNFGy8%2FbWRSe3AqI%3D
229C12
24
12.6V C.T. @ 1.9A
6.3V @ 3.8A
What you do is use one 120V winding to go across the line and use the other 120V winding as your secondary. I used this one to make a mini 5E3 with 6AK6's for output tubes. You can get away with using the high voltage winding as a secondary as the two HV windings are electrically isolated. You might not get the full 24VA out but should be fine for a couple watt amp.
Thanks for the info. Though it sounds strange and these submini amps should be getting at least 170 volts at B+ (depending on the tube) from what I have learned if you're after shrinking a classic amp circuit.
If one were to use a power transformer that's not a wallwart why not just get one that supplies B+ rather than using a power transformer with insufficient power and/or an smps? Seems a bit silly.
I'm going to dig out my submini tubes and get back on this since I need a couple of audio amps for projects and SS amps kill my buzz (hehe :icon_razz:). I believe I left off building an smps on veroboard and it didn't work out. So I need to dig that out and pick at it or perhaps as a solid alternative I could find an appropriate power transformer.
I shall return.
-KM
Quote from: Kevin Mitchell on December 28, 2017, 11:23:15 AM
If one were to use a power transformer that's not a wallwart why not just get one that supplies B+ rather than using a power transformer with insufficient power and/or an smps? Seems a bit silly.
Not sure if this refers to the Hammond 229C12 I suggested as an alternative. This one easily supplied the power, 6V and high voltage, to build a 3W 5E3. It was a good match for a 1960's 10" speaker and a full size guitar speaker (much louder). I am hoping to trade back for the amp to come home. If you need more than what the transformer delivers then you are not making a mini amp. Getting suitable sized transformers inexpensively was not an option for me at the time so I used the Hammond.
What really confused me was you suggesting to use a primary tap as a secondary. Could you perhaps share a drawing? I'm just seeing caution signals in my head :icon_lol: Maybe this is something I would find useful as power alternative.
I'll be working up a submini amp for my record player since apparently these things only put out phono or line level signals :o I'm thinking a stereo champ amp for a super simple amp build. The only thing is... would very likely need two output transformers for stereo amplification & output.
It's time to put this project back on the breadboard!
Darn computer froze on me when I tried to post my message, it was probably too wordy anyway. Here is the wiring diagram, 1-2 and 3-4 are the 120V coils, parallel them for 120V or series for 240. Because these windings are on their own plastic bobin they are 100% isolated from each other and not like a normal transformer where the one winding would be wound one the other.
(https://www.hammfg.com/files/products/229/229sch.GIF)
(https://www.hammfg.com/files/products/229/229la.GIF)
(http://img1.findic.com/229a20-KRvDbuY1-bqVwANY6o.jpg)
I I flipped the transformer so the pins faced up rather them stuck in a circuit board. Because of the plastic that supports the pins is in the way of a bolt through the mounting holes I had to file a flat on the side of the bolt head. I bought it as it gave me a flattened transformer to to put in a shallow case. I think if you live in the U.S. there are more options for a regular transformer for tubes. Shipping and brokerage fees kill me at the border.
So the unused primary becomes the high voltage secondary? Could I regulate this supply for 180V - 240V DC? I'm curious to if that tap is sufficient without any drawbacks being used as a secondary and if so - I would certainly snag a few of those transformers. This info is new to me and with my limited experience with power transformers I wouldn't consider thinking outside the box so much.
Yeah that is me, outside the box. :icon_confused:
I looked up the 5E3 6AK5 amp I built, I used a 70V transformer that had an 1/8 watt tap and I used that as a 16k load for the tubes. I biased them at their plate dissipation limit.
Quote
No info on the transformer. I have a few scavenged from renovation at work. This transformer is an oddball as all the other transformers I have are like the ones you are familiar with. The tubes want to see 10k in SE so I went for the highest ratio, for the two tubes it should be 16k with the 1/8W tap. The speaker is across the 1/8 watt tap and the common, the way it is photographed it looks like the lugs are shifted over.
For the power transformer, for a 1:1 power transformer Hammond (I am guessing others also but since I have not tested any I can not say for sure) winds the secondary with more windings than the primary to make up for losses in the transformer. Since in the above transformer both the 120V windings are suppose to be connected to the line their winding turns are the same. When you use one for the line and the other as a secondary the losses creep in and even unloaded you do not get 120V out.
Now when you take a AC voltage and multiply it by 1.414 you are calculating the peak voltage of the AC waveform. If you have a rectifier and a capacitor making dc and you have no load on it this is the voltage that will end up on the capacitor. If you draw a reasonable amount of current from it you really only get from 1.1-1.2 times the AC voltage. Also with using the transformer as I had you are loosing half your primary winding so your losses will be magnified.
Can't remember what the voltage was but say we take 110V AC, multiply it by 1.1 you get 121V and then double it you have 242V, pretty close to the 230V I ended up with. Using the transformer the way I did is far from ideal in terms of what the manufacturer intended, it just works out nicely for my application. The transformer does not have the VA rating that it would have if used normally but it has enough for my little one watt tubes.
Quote
I reduced the cathode resistor on the 6AK6's to about 360 ohms. Power supply had SS diodes using a doubler circuit and capacitance values of 22uF. This then fed a 22uF which was the plate supply. I had 230V on the plates and 192V on the screens with a 4.7k and 22uF. Through a 22k to a 22uF I had 140V for the preamp triodes. I had 112V on the cathodyne plate, 29V on the cathode. The second stage triode, 96V on the plate and 0.78V on the cathode. The input stages have 75V and 83V and the cathode with 1.1V on them with just a single 820 ohm.
Looked up a transformer I suggested for an amp like this, think it might be cheaper than the Hammond.
https://www.tubesandmore.com/products/transformer-fender-replacement-power-stand-alone-reverb
And these little buggers I like.
https://www.tubesandmore.com/products/6ak6-pentode
Beats having a triode output tube.
This is my buddy on the amp, he never played a 5E3 so he didn't know how to play with the controls. Ignore the Microsoft sign up window.
http://1drv.ms/1hDNpt3
Oh yeah, going through an old 10" out of a stereo console.
Sweet! Now I want one of those for myself :icon_lol:
I've done a fair amount of searches trying to learn the in and outs of phono preamps and came across a nice little circuit called the Mini Me. It's a stereo phono preamp using 4 6N16B tubes. I'm going to experiment with this and try my hand in designing an output preamp and amp (an integrated amplifier) using 6N16B or 6N17B triodes and 6P30B pentodes in a push-pull setup for higher output.
I've found a few projects using these tubes but no schematic that I could work from. I could replicate a low voltage (meaning around 200v) guitar amp since the 6P30B are very similar to 6v6 pentodes and tame it down for the cleanest result.
Now just have to find a couple of decent output transformers that fits the bill.
Quote from: printer2 on December 21, 2017, 10:55:07 PMYou might not get the full 24VA out but should be fine for a couple watt amp.
Not knowing for sure what the "120v secondary" would be rated at how would I know what primary fuse would be appropriate? Would I have to calculate the current consumption needed for B+ to get the ~VA for this improvised secondary winding? Could you suggest a fuse that would be safe using?
After searching around for output transformers I'm back to this thread doing the math to use line transformers :icon_lol:
Trying to understand how to get ~6k from this line matching transformer (https://www.parts-express.com/pedocs/tech-docs/300-040--70v-10w-line-matching-transformer-wiring-diagram.pdf) for a couple of 6P30B pentodes. This is something I have neglected to do last time I was picking at this project. Gonna take a few more read-throughs :icon_rolleyes:
If you were doing single-ended outputs, it would be easy. You use the equation P = V*I = V*V/R so R = V*V/P
Your 70 volt (actually 70.7 volt) outputs gives you a V*V = 5000 so if you have a 1 watt tap, you have 5000 ohms, if you have a 5 watt tap, you have 1000 ohms between the black (common) lead and the tap.
With 25 volt taps, your V*V is 625.
Push-pull operation gives you the problem of trying to balance the inputs. The black common lead goes to one plate and you have to pick a centre tap and the opposite plate tap. In this case, you can get push-pull operation from the 2.5 watt and 0.625 watt taps but the impedance is too low and although the voltages between the common and 0.625 and the 0.625 and the 2.5 has the same number of turns, the winding resistances will not be balanced. The transformer in your link seems to be drawn wrong. The highest power taps are closest to the common and the lowest power taps are closest to the opposite end from common. See this:
https://www.alliedelec.com/m/d/d8292cf7f11c601de4c651a61586c0eb.pdf
for how it should be. Use the tap with 4 times the power of the other plate tap as the centre tap so if you follow the Hammond drawing, you could use a 4 watt tap as the centre tap and the one watt tap as the opposite plate tap and get 5000 ohms plate-to-plate.
Thank you for breaking that down once more, Amptramp.
I have not settled on what format I'd like to use these tubes in but I'd like to avoid SE so I can get the most out of the setup though for the sake of tinkering I might try SE on breadboard to see how it sounds. Maybe it'll be loud enough for what I'm after.
In another forum I guess someone had gotten close to 15W out with a 3K transformer in ultra linear format. I assume that was in reference to plate to CT.
A week ago I had no idea what that meant. Just so you know where I'm at :icon_lol: So now I'm trying to find an OT that's okay for any format I may throw together on breadboard.
Quote from: Kevin Mitchell on January 10, 2018, 09:38:01 PM
Quote from: printer2 on December 21, 2017, 10:55:07 PMYou might not get the full 24VA out but should be fine for a couple watt amp.
Not knowing for sure what the "120v secondary" would be rated at how would I know what primary fuse would be appropriate? Would I have to calculate the current consumption needed for B+ to get the ~VA for this improvised secondary winding? Could you suggest a fuse that would be safe using?
After searching around for output transformers I'm back to this thread doing the math to use line transformers :icon_lol:
Trying to understand how to get ~6k from this line matching transformer (https://www.parts-express.com/pedocs/tech-docs/300-040--70v-10w-line-matching-transformer-wiring-diagram.pdf) for a couple of 6P30B pentodes. This is something I have neglected to do last time I was picking at this project. Gonna take a few more read-throughs :icon_rolleyes:
A 0.25A fast blow fuse on the primary should be fine.
Off the subject of line matching transformers (I've read they could have low freq response which is suitable for guitar but not sure about a hifi stereo design)
I have found this OT for a reasonable price (https://www.tubesandmore.com/products/transformer-output-8-w)
(https://www.tubesandmore.com/sites/default/files/associated_files/p-t291_spec.gif)
I feel this could work fine with a push-pull design with 6P30B pentodes.
EDIT:
Also I'm starting to get a little skeptical about the improvised PT having drawbacks. I may need ~2A at 12V for the entire filament circuit which a little higher than it's secondary rating so I'm unsure if pushing this and using that 120v tap as an extra secondary would be safe. But I could just be uninformed on the matter of current tolerance in this situation.
But I've also found this (https://www.tubesandmore.com/products/transformer-power)
After rectifying the taps I'd use this one should be perfect. And it's a couple bucks less ;)
Once again I took a different route on my project goal and again I have a full blown amp :icon_lol:
Super proud of this one.
(https://s9.postimg.org/84jwjkk8b/Photo_Mar_26_11_08_43_PM.jpg) (https://postimg.org/image/84jwjkk8b/)
Now that I have a better understanding of all of the possible circuit configurations I'm very much interested in creating a submini version of this amp with smaller output transformers and powered completely by a SMPS.
Always itching to tinker.
Wow, Edcor transformers and everything :icon_eek:
(http://www.joyonline.cz/sites/default/files/styles/article_main_photo/public/f24at.jpg?itok=RIvFfqkW&c=3ec6559a2596fddc972c6d62f03d505a)
Good observation.
If you can point me to a couple UL output transformers with close specs for less money then I'd see your point. These have 20 - 20khz frequency response which is more than I needed for a hifi amplifier. Not a guitar amp - a hifi amp. Most output transformers wont even list their frequency response rating - for a reason. With so much time invested into designing and building, why the hell would I cheap out and cut corners?
Final note - I got a deal on these compared to anything else that comes close. Do some research, man.
It's okay to be jealous.
Quote from: Kevin Mitchell on March 28, 2018, 04:11:32 PM
It's okay to be jealous.
And I totally am 8) I don't remember the frequency response of the cheap Chinese transformers I used in my hi-fi amp, but it sure as hell wasn't 20Hz-20kHz. Edcor isn't expensive just because they're Edcor, they're expensive because they're high quality stuff. And frankly they are reasonably priced compared to some of the other brands out there ::)
Legit question though, did you choose the chassis color before or after you got the transformers? It's a very aesthetically pleasing look 8) Any plans for a cabinet/grill over the top?
The transformers took so long to process I had plenty of time to pick at stuff. I had the whole thing painted, built and waiting for the transformers which I received two days ago - ordered in mid January. The aesthetics where designed around the transformers really.
I want to keep it open to show it off. Mostly to have a reason to talk about electronics when I have guests over. I did consider using tube guards but thought that was a bit much :icon_lol:
The amp is a version of the Poddwatt circuit if anyone is curious.
That looks awesome! Imagine small edcor transformers! I think they have a 22k 3w like the fender/hammond?
if you're going the submini route, you definetely want to take a look at this>
https://www.audioasylum.com/forums/tubediy/messages/13/edit/13824720080311181501.html (https://www.audioasylum.com/forums/tubediy/messages/13/edit/13824720080311181501.html)
or this one
https://blog-001.west.edge.storage-yahoo.jp/res/blog-33-56/matsu_kat/folder/837569/15/56212415/img_0?1229346383 (https://blog-001.west.edge.storage-yahoo.jp/res/blog-33-56/matsu_kat/folder/837569/15/56212415/img_0?1229346383)
https://blogs.yahoo.co.jp/matsu_kat/folder/837569.html?m=lc&p=5 (https://blogs.yahoo.co.jp/matsu_kat/folder/837569.html?m=lc&p=5)