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Hoffman Amps Forum image Author Topic: Tube pre amp into SS power section  (Read 1770 times)

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Offline dunner84

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Tube pre amp into SS power section
« on: December 06, 2016, 06:48:52 pm »
Hello

By order of my wife, I was tasked with getting rid of some of my "junk". While I was going through things I found an old squier 185 pro that I was given. The amp is in mint condition minus some broken jacks. They are the fender 9 pin PCB type. I never got around to ordering any due to other projects and forgetting them on larger parts orders, so I never fixed the thing. The idea was to fix it and sell it or give it away. It's not a bad sounding thing, it's just not great.

I also found a D-Pre pre amp kit from London Power that I ordered a while back, and I thought why not rip all the icky pre-amp stuff out of the squier and replace it with this cool dumble inspired pre-amp kit.

I had a look through the squier schematic, and I think I know where to hack away and connect the pre-amp, but I thought I would get some fresh eyes one it. The pre-amp kit has its own filtered power supply for the tubes, so I am really just looking at plugging it directly to the power section of this SS amp.

Here is a copy of the schematic I have. I would appreciate any insight.

Cheers

Offline shooter

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Re: Tube pre amp into SS power section
« Reply #1 on: December 06, 2016, 08:45:28 pm »
my 2c, I'd build your pre, plug it into "power amp in", and hear what happens, you like it keep it/hack it.  You'll need both low n high volts (SS) if you enter via the jack, I didn't spend any time looking for interlocks, fault circuits, etc.
Went Class C for efficiency

Offline MakerDP

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Re: Tube pre amp into SS power section
« Reply #2 on: December 07, 2016, 07:52:44 pm »
I think a nice clean solid state power amp would pair nicely with a Dumblish-style preamp. Or any preamp where the overdrive/distortion is all created there for that matter.

It's not a new concept but I believe this is an area where there is some potential commercial success going forward if someone put some real thought into it and made it sound really really nice - which I think is totally possible.

As far as your design idea, I agree with shooter... try it into the power amp in and see if it's worth turning it into something more permanent. You might want to try and power the preamp and the poweramp from the same source. Are you using the London Power power supply or are you going with your own?

I have a D-Pre kit sitting here too that I am planning on putting into a stand-alone preamp - hopefully over my three-week Christmas break.


 


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