"professional" amp conversion

[jestaudio]

This was done by a local "expert" allegly a fender clean and a marshall dirty, sounds pretty crap, very hissy and hum from a poorly thought out lead dress

I don't claim to be a great amp builder but even my nephews could do better than this, positively dangerous, I,ve started to strip it down, the good news is the traffos are ok and there are some decent components on it, any ideas on a a nice amp to build?

[ampdoc1]

What a Maroon!!!

[jestaudio]

The amp was a carslbro pa amp, 4 el34 and 5 12ax7, sockets are in good nick and the traffos are partridge

[Phil_S]

If you think you've got the real estate to do it, it seems like your iron will support a 100W Marshall variant. Build it with one F preamp, and one M, or maybe a V, or just about anything. See if you can get two different preamps in there. I think, though, you are pretty well stuck with 4x EL34 or other compatible KT-type tubes. I can't see what's wrong with that. Holy-moly that is some mess in that amp!

[martin manning]

Don't you guys recognize the work of an artist? Jackson Pollock, isn't it?

[VacuumVoodoo]

Genuine P2P ass-embly.

[jestaudio]

If you think you've got the real estate to do it, it seems like your iron will support a 100W Marshall variant. Build it with one F preamp, and one M, or maybe a V, or just about anything. See if you can get two different preamps in there. I think, though, you are pretty well stuck with 4x EL34 or other compatible KT-type tubes. I can't see what's wrong with that. Holy-moly that is some mess in that amp!

The only issue I can see is the preamp sockets are pretty close to the front though I suspect there is enough room to move them and shift the component boards forward a bit

[Structo]

Man, what a mess.

[Reeltarded]

Don't you guys recognize the work of an artist? Jackson Pollock, isn't it?

rofl!!!


LOTW. Line of the week. It will stand.

[overtone]

The amp was a carslbro pa amp, 4 el34 and 5 12ax7, sockets are in good nick and the traffos are partridge

you have the Partridges?
With that kind of iron keep it British and take it in a HiWatt or Burman direction.

[Phil_S]

If you think you've got the real estate to do it, it seems like your iron will support a 100W Marshall variant. Build it with one F preamp, and one M, or maybe a V, or just about anything. See if you can get two different preamps in there. I think, though, you are pretty well stuck with 4x EL34 or other compatible KT-type tubes. I can't see what's wrong with that. Holy-moly that is some mess in that amp!

The only issue I can see is the preamp sockets are pretty close to the front though I suspect there is enough room to move them and shift the component boards forward a bit

I've built a number of amps in recycled chassis. In general, I try as hard as I can to use the holes as-drilled. In this case, with good tube sockets already in place, I would not try to move them. I suggest trying to design around what is there.

One bit of good news is that I think I see holes for mounting can caps. You can get 3 or 4 filter caps in one can and this saves quite a bit of real estate inside the chassis, which is a big convenience when you are trying to design a retrofit.

Judging by what I see, that chassis looks to be about 16" (40cm) wide. It is harder to be sure of the width between the front and back sockets. If you have room for a 3" (75cm) or wider board, you might be able to build a double row board that allows you to organize a large number of components into a very efficient space, and you get to build it outside the chassis. If that isn't working for you, think about using terminal strips in a board-like layout. I do not think I would attempt a PTP build for a double pre-amp, as it involves too many parts. I might think about hanging tone stack components on the pots if space is tight on the board.

You've also got plenty of holes on the front panel...I think for each preamp 1 input, 1 vol, 2 tone, switch, and pilot. You don't need a standby and it is a waste of a hole. You might consider a 1 knob tone on one channel, and a traditional TMB on the other.

One of the most important things I have learned in recycling a chassis is to spend a lot of time doing the planning. Draw your layout, throw it away, draw it again...and again...and again. Eventually, your mind will open up to the possibilities. You may have to buck tradition in layouts to come up with something that works and something that fits. Above all, think long and hard about where the ground points are for each stage because it is a huge PITA to track down ground loops.

This is a great project opportunity. The chassis is a very nice platform. I, for one, would be very happy trying to build something in this one. Keep us posted. Good luck with it.

[jestaudio]

The amp was a carslbro pa amp, 4 el34 and 5 12ax7, sockets are in good nick and the traffos are partridge

you have the Partridges?
With that kind of iron keep it British and take it in a HiWatt or Burman direction.

Funny, I was looking at a hiwatt layout, the power traffo has plenty of capacity, at least 4 el34,s and 5 12ax7,s. i'll have a mull over it and see what I fancy doing,

[Jerry2013]

Can we see the Partridge Transformers? My gosh, i had a Sound City amp I had to sell regretfully, with awesome Partidge Transformers.
Would love to own a Hiwatt or another nice Sound City someday.
Do the new Reeves Amps use Partrdige Transformers?

[M Fowler]

I have a Magnavox AMP128E chassis a TAG member gave to me and it is running four 6V6 and dual 5y3 rectifiers looks like a 50w HiWatt is what this amp is screaming to be in it's next life.

Similar to this picture below but my PT is huge and stands up.

[Jerry2013]

I have a Magnavox AMP128E chassis a TAG member gave to me and it is running four 6V6 and dual 5y3 rectifiers looks like a 50w HiWatt is what this amp is screaming to be in it's next life.

Similar to this picture below but my PT is huge and stands up.

Its all about the Iron though. You gotta have the Partridge transformers to get the Hiwatt sound. Hiwatting an amp w/out Partridge Transafomers would be counterproductive.
Get a Old Sound City and Hiwatt that. Your also barking up the wrong tree with 6v6's. Hiwatts are all about huge clean headroom of the 6xel34's, and Townsend had to modify his to get a breakup even at high volumes.