Anyone built Merlin's preamps?

[Smokebreak]

Just curious about the preamps in his book, mainly the last 2 high gain ones. I'm putting the medium gain one in a 6V6 mule today.

[pullshocks]

I have been looking at the medium gain. Looking forward to hearing how you like it.

[Smokebreak]

Well, I put it in a test bed, Hammond ao43, that started life as an Express. I've had good luck using it for other Fender style circuits, but my chassis layout(which is a mess at this point) wasn't conducive to an oscillation-free amp with this one.
I took out the tone stack and got it going, but of course it had gobs of gain, more than I expected, even without the TS. I was using express NFB, so I'll try something more Fendery. I'll rework it today.

[Smokebreak]

Doh! I forgot the cap at the PI entrance, which explained why it worked w/o the tone stack. I guess my mule lives to ride another day
The amp sounds really good so far. I've only tested at bedroom volumes, but the overdrive is very smooth and balanced, and good clean accessibility. A bit less gain than a Dumble, a bit more than cranked Fender, and a bit different than a Marshall. Very very promising. Dare I say the best sounds this chassis has put out?
I'm not even sure what all pot values are in there right now, but I'm running 5k presence with 100k/8ohm feedback, and that seems to be working well.

[Zippy]

I took out the tone stack and got it going, but of course it had gobs of gain, more than I expected, even without the TS. I was using express NFB, so I'll try something more Fendery. I'll rework it today.

Does it have substantially LESS gain after you add the tone stack back in?

I don't know what TS you are using in this build, but most are pretty lossy.

[shane]

Which one of the pre-amps is it? the medium, high gain or the last very high gain one?
I've been curious about these myself.
Cheers
Shane

[Smokebreak]

Zippy, yep it had less gain with the TS in. I originally removed it temporarily to trouble shoot. It's a modified Bandmaster 6G7 stack, plate fed,that comes after 3 gain stages. Gain control after first stage, MV from treble, then PI. I've got a PPIMV, so my normal master is 1M to ground.

Shane, it's the medium gain one.

Maybe if Merlin reads this he can suggest his favorite PI/power arrangement for this preamp

[Smokebreak]

I tried a bunch of different LTP configurations and ended up with 510r cathode, 10K tail, 27K feedback resistor, and 5K/.1 presence pot. So basically, 5F6A, but on the 8ohm tap.

This amp is very aggressive! Here's a quick and dirty clip with ppimv dimed, gain control/guitar volume in different spots, tone controls at noon. At the end when everything is freaking out into wonderful feedback, gain was at 3oclock. I hadn't pushed it that much, and I kinda freaked out and just stopped. I didn't see that coming. Super fun amp. A little on the bright side for me, up close, but everything usually is these days to these ears.
https://soundcloud.com/jeremyslemenda/mediumgainpreamp

[cbass]

That sounds pretty damn good

[NickC]

Yeah, it does sound like that amp is loads of fun to play through. Nice!

[V2]

cool! Sounds raw, in a good way.

[Smokebreak]

Thanks guys. This morning it sounded so smooth at bedroom levels with full gain,but at volume it's a growler . I'm going to try some different tone stacks next.

[shane]

Yeah sounds pretty good!
Look forward to hearing how you get on with differemt tone stacks.

Cheers
Shane

[John_P_WI]

Just out of curiosity where are the examples of his preamps? I don't recall seeing them in his books...

[shane]

They are in the second edition of his preamps book
Cheers
Shane