new 18w liverpool build... it works

[cys]

Here are some pics of the 18w liverpool build I just finished using a "box of parts" from rj guitars. Thanks rj. While this is the first amp I have ever built, I have worked on my own amps over the years, including solving some issues that required extensive troubleshooting (with some study of lead dress and grounding along the way). I've built about 20 pedals. However, I prefer really small part surface mount work rather than big through hole stuff.

I used a Bridgeport mill to create additional required chassis holes (e.g., the ones for the power tubes) or slots (the OT mounting points). I used the "headphone" trick to best position the OT relative to the PT.

The amp sounds really nice. There is a moderate amount of breakup when cranked with nice harmonics (I use a Fluxtone speaker to tame volume). The amp is quiet with humbuckers, and not as quiet with single coils. I'll work on the latter by improving the grounding layout. I haven't played the amp fully enclosed yet, and that will certainly help. Any routing/grounding/lead dress suggestions appreciated.

Going forward, I'm looking to get the amp to go from moderate to semi-crazy breakup as a function of volume by changing existing component values, and/or adding new components. Any suggestions along these lines will be appreciated. I'll also be going back through old threads.

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[martin manning]

Very nice! In what orientation did the transformers end up?

[cys]

Very nice! In what orientation did the transformers end up?

Thank you. Best orientation incorporated a slight offset as indicated.

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[cys]

I've spent some time tweaking this Liverpool build and have it in a good place for now. Adding the R* stopper for V1a shown as optional in the schematic added noticeable stability. I choose 150k for R7 and 0.0044uF for C8 to make it edgier, after initially installing 68k and 0.0022uF. I had a fizz problem, and tried adding bypass caps all over with no noticeable change, so I removed them. On the assumption that it was the el-84's that were fizzing, I tried swapping in different bias resistors. The initial build used a value of 130 Ohm. I tried 140 Ohm and it helped with the fizz, so that value remains in the amp. All of these tweaks had a side effect of making the presence control sound much better than it did before the changes. Indeed I had the presence disconnected for a while because of how it sounded initially. In the end I noticed having the presence control in the circuit was "essential" for making single coils sound good. However, having the presence control in or out of the circuit gave good results for humbuckers, and having the presence out of the circuit gave "spectacular" results for some humbuckers. There are some interesting CTS 5K pots on eBay at the moment with a push pull switch. I installed one of these for the presence control so I have the option of with and without. I also picked up a mahogany chassis off of eBay which showed in about 3 weeks, unfinished. I kept the finish simple with tung oil.

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[joeboo88]

your cabinet looks great... I really love my Liverpool, and I am also in the process of finishing my cabinet. I think I will copy you and use the tung oil.
Good job

[gktamps]

Beautiful build!
What transformers did you use?

[cys]

Thanks. Rj set me up with Heyboer transformers, HTS-12651 and HTS-12652.

[cys]

I decided to give the "Ruby Mod" a try to alleviate the fizzy note decay that was present in the build with a 120 ohm or 130 ohm bias resistor. My temporary fix was moving to a 140 ohm resistor, which helped. I tried 9v zener diodes along with 1N4007's going back to a 130 ohm bias resistor. This had the affect of removing the monotonic fizz note trail and replaced it with subtle hints of modulated fizz here a there at the end of single note decay. I like it and will keep it this way for a week before adding a cut control. Two side effects are that "presence out of the circuit" sounds better, and single coils have now taken a big lead over hum buckers with respect to tone. This is fine with me as I prefer Strats. Without NFB the amp produces a "whine" when everything is dimed that gets absorbed in the mix when playing. I'm holding out that the cut control may help alleviate this. The Ruby Mod has helped with some odd artifacts in addition to the fizz, like non-musical "swirling" treble notes with the guitar volume attenuated with one particular speaker. All fixed now.

[cys]

The Ruby mod lasted only a day -- I removed the diodes and moved back to the 140 ohm bias resistor. The harmonics were better and the amp was much less well behaved as configured before the Ruby mod. I need to be able to go from Hendrix cleans to Stooges using just the guitar volume. I did add a treble cut control yesterday.

[cys]

Just a follow up to say that I've left the Trainwreck build untouched since my last post on April 24th. It's in a great place sonically, and was completely what I was seeking. No fizz. Plenty of harmonics and distortion. I often play with everything dimed. I find it works well with both single coils and humbuckers. I had to work a bit to get the sound I wanted with my Les Paul though -- about 5 humbucker swaps, and then it delivers tone-wise only through a Greenback but not a EVM-12L (both from Fluxtone).

P.S.: I have all the parts on hand to build an ODS #183. I'm just curious to see what this circuit offers.

[ViperDoc]

Would love to hear some clips if you've got em. The Pete Thorn video had me shelling out for parts in no time. Still haven't built one yet. Can't decide whether that or an Express would be better for me. Usually the answer to "Hmmm....Liverpool? or Express?" is always, "Yes."

[Colossal]

Would love to hear some clips if you've got em. The Pete Thorn video had me shelling out for parts in no time. Still haven't built one yet. Can't decide whether that or an Express would be better for me. Usually the answer to "Hmmm....Liverpool? or Express?" is always, "Yes."

You think you can handle a woman like that, dude?

[ViperDoc]

Would love to hear some clips if you've got em. The Pete Thorn video had me shelling out for parts in no time. Still haven't built one yet. Can't decide whether that or an Express would be better for me. Usually the answer to "Hmmm....Liverpool? or Express?" is always, "Yes."

You think you can handle a woman like that, dude?

Well, I'm sure I could keep myself happy, no problem!

[cys]

Would love to hear some clips if you've got em. The Pete Thorn video had me shelling out for parts in no time. Still haven't built one yet. Can't decide whether that or an Express would be better for me. Usually the answer to "Hmmm....Liverpool? or Express?" is always, "Yes."

I don't have any clips. That video swayed me to build a Liverpool. I just went back and relistened to it. I think my amp would sound similar... in his hands .