30v Sopht Amp output transformer

Started by El Heisenberg, March 20, 2011, 11:23:33 AM

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El Heisenberg

Gunna try this :

http://www.sophtamps.ca/mambo/index.php?option=com_content&task=view&id=26&Itemid=38




and would rather not make an order online for the 119DA transformer.

Says can use a 70v line matching transformer.

"You can use a 70V line transformer as the output transformer instead of the Hammond 119DA that I use. Both will do fine. If you are using the 70V line transformer, use the 2.5W tap as a primary and the appropriate ohm for the secondary matching your speaker. 70V line transformers can be had for a few dollars."

I found this in town:

http://www.frys.com/product/4785069?site=sr:SEARCH:MAIN_RSLT_PG



Will this work alright? I wouldn't know which the 2.5W tap is..
"Your meth is good, Jesse. As good as mine."

El Heisenberg

"Your meth is good, Jesse. As good as mine."

slacker

#2
That should work, a quick google finds this http://www.weisd.com/store2/PHIMT2570.php which says it has the correct taps. It will probably tell you on it which tap is the common one and what all the other ones are.

El Heisenberg

Thanks you thanks you!

Ive been wanting to build an ALL tube amp but the parts (tubes, hi voltage caps, tranformers) are hard fot me to find locally. Cabt buy online. No cards.

This amp isnt supposed to sound super stellar. But way cheaper than a Firefly and and easier to find parts.

"Your meth is good, Jesse. As good as mine."

petemoore

#4
  600 ohm to 8 ohm secondary
  what the ratio specified is.
 Personally I'd look for the first SE Transformer around, something attached to a speaker [sometimes hooked to a frame] or amplifier...
 See what the impedance ratio is of the transformer, this is the set of numbers you're looking for.
 It's safe to assume you won't exceed 2.5watts or that it won't really matter until you ever would find another use for the xformer...ie if it's in the I-ratio ballpark..you can't break it with a small bottle using 30v of plate "push".
 Any old tube radio might have a little OT xformer.
 I've used power transformers but prefer the old audio stuff.
   For techniques for checking the transformers ratings/ratio see google, use 2vAC to put a wave into primary ll secondary coupling to see what comes out.
   basically you need a certain small amount of voltage, smaller the better after that in case the secondary sees it and the primary just happens to be 20:1 or something...10v x 20 = 200v, dinky wallwart is good safety starting point.
Convention creates following, following creates convention.

El Heisenberg

I wish i could find old tube stuff lyig aroubd. Unfortunately i think the city i live in is much too young to have any tube technology just lying around for me to pirate.
"Your meth is good, Jesse. As good as mine."

Ronsonic

Quote from: El Heisenberg on March 20, 2011, 08:58:56 PM
I wish i could find old tube stuff lyig aroubd. Unfortunately i think the city i live in is much too young to have any tube technology just lying around for me to pirate.

I'm in Tampa, which barely existed thirty years ago. Raid flea markets, yard sales, church sales are good and of course any sort of old thrift stores like Goodwill or St Vincent dePaul.  Just keep scoping for old "singing furniture" consoles and receivers older than the polished aluminum 70s. Bakelite radios even ancient televisions and tape recorders could have very usable components like tubes and transformers.

Old organs can contain a bucket full of tubes and a trunk full of power supply and amplifier components.

I've even bought a console stereo at a thrift store, gutted it in the parking lot in the back of the van and then drove around back and donated the carcass. "It doesn't have anything in there, but maybe you can still sell it." They took it.

The stuff is out there. Maybe not as much in your town, but look where others didn't think to, or where the pro's don't want to bother with.
http://ronbalesfx.blogspot.com
My Blog of FX, Gear and Amp Services and DIY Info

El Heisenberg

Hey


Can i use this audio transformer from radioshack??

http://www.radioshack.com/product/index.jsp?productId=2103254

Its the same one used in bobtavia.

Theres a review on radioshacks site that says the guy use it for a 12K5 amp.

I think its 1k to 8 ohm. So could i use the 1k as primary or maybe center tap for 500 ohm?
"Your meth is good, Jesse. As good as mine."

El Heisenberg

I also found one of these laying around:

http://www.mouser.com/Search/m_ProductDetail.aspx?Xicon/42KM014/&qs=Vn%252bylxfhaHpujuLPukELRw==


So i got 3 choices. The local Frys doesnt have thw line transformer and i have or can get the two smaller ones. Hammond one i outta the question.

Will the smaller ones work??
"Your meth is good, Jesse. As good as mine."

markeebee

Quote from: Ronsonic on March 20, 2011, 10:41:27 PM

I've even bought a console stereo at a thrift store, gutted it in the parking lot in the back of the van and then drove around back and donated the carcass. "It doesn't have anything in there, but maybe you can still sell it." They took it.


Note to El H: just do this with goods, not staff.  I've seen some of your posts.

You can pick up tube radios on eBay for less than a fiver if you're lucky. They'll have tubes, iron, mojo resistors, maybe even reusable caps.

El Heisenberg

"Your meth is good, Jesse. As good as mine."

markeebee


El Heisenberg

"Your meth is good, Jesse. As good as mine."

El Heisenberg

Or I will find you and watch you, until you notice...
"Your meth is good, Jesse. As good as mine."

markeebee

Just to be straight: there are NO posts in which you appear thuggish or psychopathic.

El Heisenberg

Ok, hey, I went and ordered most of the parts.


A 1n4004 will work fine for the rectifier diode right?
"Your meth is good, Jesse. As good as mine."