Reverse engineering amps-any homebrewers here?

[Quencho092]

Just curious-how hard is it to really reverse engineer an old school amp? Say a deluxe reverb or something to that effect. With a head chassis, a transformer, mounting board, sockets, and the caps and resistors, can't anyone just follow the circuit of a fender twin and make their own handwired masterpiece?

I'm really interested in this kind of stuff, and just out of curiosity, anyone got the schematics for any blackface circuit?

 

[the guy who invented fire]

Re: Reverse engineering amps-any homebrewers here?

Just curious-how hard is it to really reverse engineer an old school amp? Say a deluxe reverb or something to that effect. With a head chassis, a transformer, mounting board, sockets, and the caps and resistors, can't anyone just follow the circuit of a fender twin and make their own handwired masterpiece?

I'm really interested in this kind of stuff, and just out of curiosity, anyone got the schematics for any blackface circuit?

If you've never tried anything like that at all...I would say get a it first. A tweed champ is a good starting point...if you feel good about your skills, and think you can do it a Tweed Deluxe is a good place to start (not to mention a killer amp!). Maybe Scott will chime in...he is the Roll your own amp builder and he has done it more that I have!

 

[Imp]

Re: Reverse engineering amps-any homebrewers here?

www.18watt.com

www.ax84.com

couple of warm-up projects?

 

[Quencho092]

Re: Reverse engineering amps-any homebrewers here?

bump...guy who invented fire, have you ever done a tweed deluxe before? and how much harder would a blackface be? i took a look at the schematics and it looks a bit baffling, but if i take my time and do it one joint at a time, i think its possible.

 

[Luke Duke]

Re: Reverse engineering amps-any homebrewers here?

A few years back I bought a cd off ebay that had all of the British amp schematics except Marshall. I was planning on building an AC-30 with more gain amp. It was well laid out and made sense. BUT I got my Z and that project kinda went out the window. I was looking at buying Hoffman boards and such there's lots of internet sources. The trannies are the most expensive part of the actual amp.

Luke

 

[Blue Calx]

Re: Reverse engineering amps-any homebrewers here?

Thanks for the links, Imp!

 

[Lewguitar]

Re: Reverse engineering amps-any homebrewers here?

Here: http://www.missionamps.com

Bruce is my brother and his tweed 5E3 Deluxe kit is based on my own original tweed Deluxes that Bruce reverse engineered...including the transformers, which are the most critical part, the heart and soul of any amp, and the most difficult part to get right.

Bruce's tweed 5E3 kits sound better than some 50's 5E3's! Like old guitars, every old 5E3 has it's own personality.

You can't make them all sound identical. The differences in tone between my two oldies is very, very subtle, but it is simply the difference due to the sum of the differences in the tolerences of all of the parts.

 

[Curly]

Re: Reverse engineering amps-any homebrewers here?

I'd recommend doing some research first.

Most good amp books, such as Weber's first book, will have the layout diagram, as well as the schematic.

And, yes, the tweed Deluxe is a good first build, since the kit has been tested through lots of builders, and there's a good support group on the web.

I'd just be sure you understand what the 5E3 is first, so you aren't trying to get more clean headroom out of an amp that's not known for that.
A tweed Deluxe is different than a blackface amp.

 

[Lewguitar]

Re: Reverse engineering amps-any homebrewers here?

I'd recommend doing some research first.

Most good amp books, such as Weber's first book, will have the layout diagram, as well as the schematic.

And, yes, the tweed Deluxe is a good first build, since the kit has been tested through lots of builders, and there's a good support group on the web.

I'd just be sure you understand what the 5E3 is first, so you aren't trying to get more clean headroom out of an amp that's not known for that.
A tweed Deluxe is different than a blackface amp.

All true!

Gerald Weber's books are excellant and highly recommended. Even Dan Torre's book, Inside Tube Guitar Amps, has helpful info for beginning amp builders...though Dan keeps it simple and some engineering types criticize his definitions of things. I think it's a good and helpful book for guitarists who want to work on thier own amps though.

The key to getting clean headroom from a 5E3 Deluxe is to use the best tubes you can afford and to use the VERY BEST 12" SPEAKER you can afford: one that is very efficient and gives you alot of volume per watt of power.

The original speakers in those amps are not very efficient. Jensen P12R's break up very easily. As do the Jensen C12Q my '58 tweed Deluxe came with.

The Celestion Alnico Blue G12 speaker is about $200...but it's the only one I'd use in a tweed Deluxe. Unless you can get your hands on a '58 blueframe jensen P12Q with the original cone...that's another really good one but still not the equal of the Celestion G12 Alnico Blue or Silver.

It takes a special speaker to get both balls and clarity from a 5E3: one with strong bass, strong highs (and mids) and high efficiency.

Lew