A few questions regarding my new Liverpool build

[Ledvedder5150]

I've been playing my new build all night. Man, this thing is killer. Very different from my other amps (mostly Marshalls), but in a great way. I love the picking and volume dynamics of it. Clean to mean with just the guitar volume and picking power.

But, with that said, there are a few things I'd like to tweak. I play mainly HB guitars, so I'd like to reduce the low end a bit. I've read some posts that recommend lowering one or both of the 22uF bypass caps. Has anyone tried this? I don't want to lose that volume control of the dynamics. Another area I thought about was lowering the PI input cap from 100nF to something like 47nF, or even 22nF. Anyone tried this?

I'd also love to have a master volume, but I'm not sure it would work well with this design, or even which type would be best. Thoughts?

Also, any preamp and power tube recommendations are welcome!

[guitarmike2107]

22nf on the phase invertor still gives full response, it is what I have in mine and I can't see any reason to make it bigger, might try smaller though.

I am going to change the second bypass cap to 0.68uf - for a 2.7k/0.68uf cathode arrangement. Tighter bass and you will probably be able to turn up the bass more.

With the 68k/2.2n coupling set up the amp really does not have any low bass attenuation, the 68k/2.2n is more of a top boost than bass cut.

Glad you are enjoying the amp!

[Ledvedder5150]

22nf on the phase invertor still gives full response, it is what I have in mine and I can't see any reason to make it bigger, might try smaller though.

I am going to change the second bypass cap to 0.68uf - for a 2.7k/0.68uf cathode arrangement. Tighter bass and you will probably be able to turn up the bass more.

With the 68k/2.2n coupling set up the amp really does not have any low bass attenuation, the 68k/2.2n is more of a top boost than bass cut.

Glad you are enjoying the amp!

Yep, it's great so far! And thank you for all of your help during my build. Now this is the fun part for me. Tweaking things to get exactly what I want out of the amp. I may try twisting the heaters just for the heck of it, to see if it makes any difference. I've never compared it both ways in the same build. This way I can either prove or put that myth to rest. And perhaps elevating the heater center tap like you mentioned in your message. I did that on a high gain Marshall style build and it did help.

The only NOS type 12ax7 tubes I have are an RFT and a few Sylvanias. Everything else is current production. And only JJ EL84's.

[dorrisant]

PPIMV (Lar-Mar) sounds great for most of the pot rotation... Although it thins out when you start rolling it more than half way.

[Ledvedder5150]

PPIMV (Lar-Mar) sounds great for most of the pot rotation... Although it thins out when you start rolling it more than half way.

Which one is that? The dual 1M pot with 2M2 resistors in place of the 220k resistors?

[WiderGates]

Hello,
you have to use a 250K Stereo pot with 2M2 resistors.

[Ledvedder5150]

Hello,
you have to use a 250K Stereo pot with 2M2 resistors.

Audio or linear taper? I've read that audio taper doesn't seem to work so well.

[WiderGates]

I would use audio. For me linear comes up too fast.
You can try what you like better.

[Reeltarded]

Where is your volume setting? Use the small bright and moderate volume until it sounds and feels the same. 6-7 is end of the line for me. Just where the bright collapses. I hear these like Fenders and stay out of the end of travel because it sounds bad to me. Use the tone controls. They work oddly. Middle all tone, set volume, then boost or cut.

I would stay away from circuit mods for a couple weeks. Get used to the amp. It's like a sportscar. The controls are close ratios.

rock

[Ledvedder5150]

Where is your volume setting? Use the small bright and moderate volume until it sounds and feels the same. 6-7 is end of the line for me. Just where the bright collapses. I hear these like Fenders and stay out of the end of travel because it sounds bad to me. Use the tone controls. They work oddly. Middle all tone, set volume, then boost or cut.

I would stay away from circuit mods for a couple weeks. Get used to the amp. It's like a sportscar. The controls are close ratios.

rock

I'm liking between 10 and 12 o'clock on the volume. Presence 12:00, bass 9 or 10:00, mids and treble 1:00-2:00. I'm digging both bright caps for different reasons. The 500pF gives it a more modern tone.

[Reeltarded]

Just checking what you had going. I like that area best too.

[Ledvedder5150]

Heck, I'm gonna give the ppimv and cut control a shot. I have a PPIMV in my 50w Plexi as well as my DC30 clone, so I know what to expect. I realize they aren't perfect, and will never be the same as cranking the snot out of the power section. But if it's good enough in a pinch instead of having to lug my power station to band rehearsal or a gig, I'll be happy with it.

I drilled for the 2 new pots, but didn't drill out the faceplate yet, in case I decide I don't like them.

20230117_194124.jpg

20230117_192842.jpg

[Colossal]

The resistors on your PPIMV pot....are those 220k? Red-red-yellow? Or Red-red-green, 2M2 and the photo is overexposed, making the green band seem yellow?

[Ledvedder5150]

The resistors on your PPIMV pot....are those 220k? Red-red-yellow? Or Red-red-green, 2M2 and the photo is overexposed, making the green band seem yellow?

They're 2M2. Samsung phones and their overexposed pictures. Grrr!

Does anyone else not get email notifications about thread posts? Or is it just me?

[Colossal]

The resistors on your PPIMV pot....are those 220k? Red-red-yellow? Or Red-red-green, 2M2 and the photo is overexposed, making the green band seem yellow?

They're 2M2. Samsung phones and their overexposed pictures. Grrr!

Does anyone else not get email notifications about thread posts? Or is it just me?

Ok, just checking on those resistors.

Regarding thread post and private mail notifications, sadly the forum software has some issues which can't be corrected anymore. Phil, our intrepid administrator, has fixed things in the past but the software needs an update and the site owner will not respond, so it hangs in limbo It's annoying, but best to just routinely check your active threads.