Took some time off to build an amp. It is now complete!!

[scottosan]

Here are the clips of my first amp build. I was going for an agressive tone, since I have a JMP, JCM800, and a Bogner XTC. I kind of miss my Uberschall , but anyway, I wanted to use something along the layout of the marshall so I could use my amps as references for all of the layout an wiring. From that point I set out to get as much gain and agressive voicing as possible out of the 3 gain stage layout, so I studied a butt load of schematics. My main concern was noise and oscillation when I started jacking with the gains stages. I never though I could get this much gain, but there are tons of good resources on the internet for suggestion on noise control.

gain - 12:00
master- 10:00
Treble - 12:00
Middle- 12:00
Bass 10:00
Presence- 12:00
Depth 10:00

The Depth control Rocks BTW


http://home.comcast.net/~scottosan2004/hb2.mp3

The part that sucked the most, was drilling the chassis.

[petemoore]

Super !!! Looks and sounds Fantastic, Aren't you the happy dog !!!
 Nice work BTW, looks like it's built like you [and I] would want it...

[scottosan]

Super !!! Looks and sounds Fantastic, Aren't you the happy dog !!!
 Nice work BTW, looks like it's built like you [and I] would want it...

If I could do one thing different, I would have gotten a thicker chassis.  THis one is fine and supports the trannies just fine, but it could be thicker.  All in all, I did it for a tad over $400

[robbiemcm]

That does look amazing. If you don't mind me asking though... what contributed to the main cost of this project? And I'm sure I (and many others) would be interested in the plans for this and the research you did to keep noise down and such, unless you don't want to release that. Your choice

Thanks for the pics, enjoy your new machine
Robbie

[scottosan]

That does look amazing. If you don't mind me asking though... what contributed to the main cost of this project? And I'm sure I (and many others) would be interested in the plans for this and the research you did to keep noise down and such, unless you don't want to release that. Your choice

Thanks for the pics, enjoy your new machine
Robbie

The main costs are:

Output Transformer: $90
Power Transformer: $100
Filter Capacitors: $10 x 3
Chassis $30
plus jacks, turret board, compnents, potentiometer, etc//

[petemoore]

Lighter overall weight is an advantage.

[birt]

very nice!
a schem of the preamp and tonestack would be even nicer :lol:

[mrsage]

Not to hijack this thread (completely ), but I thought I'd post my amp build as well, since folks around here helped me with a bit of troubleshooting!

http://tinypic.com/5flm3b
http://tinypic.com/5flls0
http://tinypic.com/5flm9x
http://tinypic.com/5fllpi
http://tinypic.com/5fllwy
http://tinypic.com/5flmdk

www.marshamps.com

Got the whole kit for a great price...including the cab, chassis, speaker, tubes, and everything...

And it sounds great!

(that is all...carry on with your original thread )

[Paul Marossy]

The part that sucked the most, was drilling the chassis.

I hear ya. I felt the same way when I made my Spitfire clone!

Nice work, too!  :wink:

[davebungo]

Great sound!!  What power output is it?  It would be good to hear some more samples, maybe a lower gain setting and some lead playing.

[spudulike]

:shock:

Way beyond me but that sounds really good.
Nice one.

[ragtime8922]

Awesome! I took time away from fx for the same reason, tubes! Only I just read and read and read some more. I then designed my own tube amp breadboard/test rig. This was a must after comming from the FX world and starting to experiment with tubes. After my second experiment using plywood and screws I had to do something.

Anyway, congrats on the build and I second the request for the schematic but fully understand if you want to hang on to it.

[Connoisseur of Distortion]

that sounds fantastic. i'd also like to see a schemo, but also acknowledge that said schemo is entirely your business, and won't hold it against you if you wish to hold onto it  :wink:

[robbiemcm]

Hate to have to throw the noob questions at you, but I gotta learn some time.

Why is there a standby? I've heard about this from a friend.
What exactly happens in terms of the circuit when you switch it to standby?
When you want to ply through the amp should standby be on or off?

And these three are a tad off topic, but you can help out with it if you want...

Once you have amplified a circuit like that, is it still fine to put the signal through a stombox with standard switches and stuff, like an ABY box?
For speakers do you just connect them up and they myseriously work?
If that's what you do with speakers, why are they usually so bulky? Or do they have amplifying circuits inside them aswell?

[AL]

Beautiful amp.  What type of components did you use - transformers, caps etc? And where did you get the turret board?  Really nice work - very inspiring.

AL

[Melanhead]

Way cool!!! ... I built one a few years back but nowhere near as cool ... It's something I'd love to do when I get time ... My kids are now 1.5 and 3.5 so I figure I should be ready to build one in about 20 years!!!

Thanks for sharing ....

[scottosan]

Hate to have to throw the noob questions at you, but I gotta learn some time.

Why is there a standby? I've heard about this from a friend.
What exactly happens in terms of the circuit when you switch it to standby?
When you want to ply through the amp should standby be on or off?

And these three are a tad off topic, but you can help out with it if you want...

Once you have amplified a circuit like that, is it still fine to put the signal through a stombox with standard switches and stuff, like an ABY box?
For speakers do you just connect them up and they myseriously work?
If that's what you do with speakers, why are they usually so bulky? Or do they have amplifying circuits inside them aswell?

This explanation is kind of crude and applies to a typical circuit in A/B mode.
For simplicity sake, let refer to just 4 parts of the tubes.
1. Heaters
2. Grid
3. Plate
4. cathode

Your power transformer convert wall power to a specified power.  The transformer also has a 6.3volt tap that is used to supply low voltage to the heaters of the tube.  Tubes need to be properly warmed before sending 250-500 volts to the plates.

When power is on but the other switch is in the standy position, then the only part of the circuit getting power is the heaters(for the reason I said above.  When you take the amp of standby, Power is converted to DC then supplied to main circuit with filtering points throughout the circuit.  You also havea bias circuit(which operated on -DC Voltage.  

High voltage to the tubes is supplied the the plates of the tubes.

The input or signal comes in the grid of the tubes.

Your cathode is the path to ground from the tube.  The lower the resistor used, the more gain you get.  You used different value capacitors in parallel with these resistors to boost certian frequencies.  

The processed signal then leaves the plate(I know we said the plate supplies the voltage). This is where a capacitor is used to remove the DC current from the path prior to feeding the next grid/gainstage. At the end of the gain stages, you use a cathode follower circuit to place you tonestack. After the tonestack, the signal is feed to the phase inverter which drives the output stage. One half of the signal(top of the wave) is fed to half of the output tubes and the other half(bottom of wave) goes to the ohter half of the output tubes. The power tubes then feed signal to the output transformer which powers your speaker

[Doug_H]

Beautiful work! Looks and sounds great.

Doug

[scottosan]

Beautiful amp.  What type of components did you use - transformers, caps etc? And where did you get the turret board?  Really nice work - very inspiring.

AL

I used a bunch of different types.  JJ filter caps,  Mallory 150, Sozo, and micas for the signal capsl.  I used metal film, carbon comp and carbon film resistors.  I used Marshall 50 transformers and a Mercury Magnetics 2H choke.

[ragtime8922]

[/quote]This explanation is kind of crude and applies to a typical circuit in A/B mode.
For simplicity sake, let refer to just 4 parts of the tubes.
1. Heaters
2. Grid
3. Plate
4. cathode

Your power transformer convert wall power to a specified power.  The transformer also has a 6.3volt tap that is used to supply low voltage to the heaters of the tube.  Tubes need to be properly warmed before sending 250-500 volts to the plates.

When power is on but the other switch is in the standy position, then the only part of the circuit getting power is the heaters(for the reason I said above.  When you take the amp of standby, Power is converted to DC then supplied to main circuit with filtering points throughout the circuit.  You also havea bias circuit(which operated on -DC Voltage.  

High voltage to the tubes is supplied the the plates of the tubes.

The input or signal comes in the grid of the tubes.

Your cathode is the path to ground from the tube.  The lower the resistor used, the more gain you get.  You used different value capacitors in parallel with these resistors to boost certian frequencies.  

The processed signal then leaves the plate(I know we said the plate supplies the voltage). This is where a capacitor is used to remove the DC current from the path prior to feeding the next grid/gainstage. At the end of the gain stages, you use a cathode follower circuit to place you tonestack. After the tonestack, the signal is feed to the phase inverter which drives the output stage. One half of the signal(top of the wave) is fed to half of the output tubes and the other half(bottom of wave) goes to the ohter half of the output tubes. The power tubes then feed signal to the output transformer which powers your speaker[/quote]

robbiemcm, scotosan's explanation is awesome. I recently read two complete books on tubes and read brief portions of countless other publications and some of them barely cover what he did in a simple thread reply.
      That response should be at the beginning of every tube book. This way a beginner won't have to read 4 chapters (or 4 books sometimes) to find out that:
   "Your cathode is the path to ground from the tube.  The lower the resistor used, the more gain you get."

Nice job scotosan!