The Amp Garage

What coupling cap and resistor have you got between the 2nd and 3rd stages? 2.2nF and 68k. Try replacing the 2.2nF with 1.5nF or even 1nF, see if that takes you in the right direction. I'm not sure what configurations Liverpools generally have if I'm honest, just that it ranges from .001uF - .01uF ...

What coupling cap and resistor have you got between the 2nd and 3rd stages?

If less drive is the intended outcome then I would have an actual voltage divider between stages 2 and 3 to bring it down a tad, whilst adjusting the coupling capacitor at the same time if needed to keep the bass cut the same.

… some cathode biased class AB amps are specced at 80%ish idle bias, some even biased cold at 55% and some at max dissipation. … Bear in mind that bias can be tweaked to operate closer to class A. But another approach is to increase the load impedance. Might that align with the 55% example? It’s ab...

I went through a similar thing with my last amp which was Class AB Cathode Biased. I had it at 70% and it just sounded meh, now biased at 95% it is worlds better. I was actually going to write an article on this as I did a fair bit of research but a house move got in the way, so I'll try and sum it ...

It's the same as the Express configuration. Single resistor to ground after the .0047uF. The .0047uF goes from the anode of the previous stage directly to the grid of the following stage. The concorde does have more gain in the way of a hotter biased 3rd stage followed by a cathode follower as well....

I think the Concorde has a .0047uF/330K configuration, cuts the bass a tad. I also believe Pete Thorn has a Concorde and he had the bass cut even more. Try bringing that .1uF down until it's to your liking.

Sorry for the late response, I had the probes set to 10x.

And that's quite interesting Catalin! Nice little trick worth remembering.

I used Edcor on my last build, sounded good and looks good! https://edcorusa.com/collections/tube-amplifier-push-pull-output-transformer/products/xpp20l-8k-20w-6-6k-ohms-push-pull-tube-output-transformer https://edcorusa.com/collections/tube-amplifier-push-pull-output-transformer/products/cxpp25-6-6...

There is a Trainwreck Express with a single tone control. It also has a volume control. https://m.facebook.com/story.php?story_fbid=pfbid0gxjGXiTnuuCYyC1xUvq1GTLU3eTguo2Fx7ZMJxH1pBypWttToh3xpfVKP2SEBog3l&id=445213072194215 I’ve no idea on what volume control it uses, but I wondered if the tonestack ...

https://www.dailymail.co.uk/news/articl ... -plot.html

http://www.davidjpym.com/page459.html

Doesn't sound too good.

Interesting, so it still has the 2.7K/.22uF bypass on the 3rd stage? I thought the standard had less gain than the OD100SE. I copy here some comments written by bnouille (Bruno Durand IIRC): OD100 SE+ is just basically the same as the 3+ .Same clean and lead channel .The so called "crunch" channel i...

Fair point. I do have a partial schematic for the OD100SE that shows the lead channel, although it's just the lead channel from the CAE 3+SE and doesn't show the power supply so it won't be of much help am afraid. If the amp you get in is a Standard then it'd be great if you could share the details ...

Husky hasn't been active on this forum since 2015 am afraid. He might still be active on gearpage though. Failing that, speak to Suhr customer support, although they might just ask you to bring the amp in as they give a lifetime warranty.

They all look like that am afraid. The model will be on the back.