Liverpool critical voltages

[harryk]

Hi all! I just started my Liverpool 2xEL84 project. Now I would like to know what are voltages needed in pre an power amp in plates and cathodes. I have a schem where there are only voltages of rail voltages but no more. My PT is 2x300V/100 mA and EZ81 rectification which differs a little from the original schem. Can somebody help? Harry

[dartanion]

That PT is quite a bit over spec'd on the HT Taps. The Liverpool uses a 260-0-260 PT, thus you will have to find a way to drop voltage, or use a different PT.

[harryk]

I was first aiming to do a Marshall 18W poweramp to this amp but now I have to consider to change PT if I want that authentic Liverpool. Which part in Liverpool has a bigger role soundwise - is it poweramp or preamp or a combination of both? Regards Harry

[dartanion]

There is nothing wrong with mating the Liverpool to a Marshall 18watt PA, but you'll have to tweak it to get it right. I am actually in the process of building an 18watt Liverpool that I will share info on when I'm done.

Ken designed the Wrecks to distort in the PA, then the PI, then the clipping stage of the preamp. An 18watt PA shouldn't have many issues with doing this as it is designed to have primarily PA distortion with a little PI distortion as well.

[harryk]

That is nice to hear. It is very good to share experiences with skilled people when building these amps. To me this is only hobby but I still want to make the best sounding tube guitar amps here in Finland. I was asking plate and cathode voltages of Liverpool but nobody is responsing. Are they a top secret or what is the reason not to share them with me? To me it would be a big help to get these voltages to adjust my Liverpool. Regards Harry

[dartanion]

If you look at the Mark Abbott schematic, he notes all the different rail voltages, but no specific test points. I haven't seen a schematic with voltages either, and I don't have one on hand at this time to measurements from. You can calculate what each voltage should be if you want to.

[gearhead]

I was asking plate and cathode voltages of Liverpool but nobody is responsing. Are they a top secret or what is the reason not to share them with me? To me it would be a big help to get these voltages to adjust my Liverpool. Regards Harry

Try doing a search. I thought I've seen them posted at one time or another.

There are no big secrets. You ask a question and expect folks to hand you the answer (in less than a day)? Do some research first.

[harryk]

I always do the search first before asking anything here. However I did not find any information concerning these voltages. I can always proceed with rail voltages because I know the exact component values needed. I do not want to rude, but I was only wandering if there are some hidden secrets behind these voltages because I cannot find them. This forum is fantastic help to my amp building and I am very happy to be a member here. Regards Harry

[DerStever]

Actually guys (and gals) Harry has a good point. ON 18watt.com they had made up some downloadable forms which listed the pins on each tube and a column so you could record voltages - some of the more experienced builds by Richie and Graydon etc etc were then posted on the site so other builders and experimenters could see if they were in the ball park.

I found it reasurring and very helpful. Maybe we could do something like that here?

[gearhead]

https://tubeamparchive.com/viewtopic.ph ... ol+voltage

for the power section. Preamp voltages are a bit dicier.

[harryk]

:DOne stupid question concerning Liverpool rail voltage resistors. There is a 1 kohm/25W resistor between B1 and B2 which is 25 W. Is there a real reason for that huge wattage. To my mind reducing voltage and dissipation do not need that big resistor. Normally these resistors are of 3-5W in the rail. Am I wrong? Regards Harry

[Humbucker]

Welcome, Mr. Bluetone. Was wondering when you should enter
It seems there are a few TW clones in Finland and you're making a few more
Cheers!

Humbucker, a proud owner of two Express clones.

[harryk]

Hi Humbucer! Do you have any idea why the wattage in rail voltage B1 resistor 1kohm is 25W? To me it seems overrated when thinking that there will be only 2xEL84 in my version of Liverpool. It is nice to meet Finnish fellows in international tube amp forums. This Ampgarge is excellent source of information to Twreck amps. I just noticed that some Vintage shop is selling one of the first Twrecks with 75 000 $. In this case these amps have to be pretty good. I am trying to make my first Twreck version just now. Reagrds Harry Bluetone

[Humbucker]

Hi Bluetone,
no clue but some things are best left unanswered...
but seriously, it is overrated; I'll check it with a knowledgeable friend and get back to you a.s.a.p.
BTW, you should inject some clips to your net site. Eyes don't listen

[harryk]

Hi Humbucker! I know that I should buy a USB mike and do some sound clips to my web pages (www.bluetone.fi) but building amps and playing once a week with my rock band besides my everyday job seems to take all energy. If you live somewhere in south Finland (I live in Espoo)and you are a modest guitar player we could generate those clips together. You find my contact information from my pages. I am still missing some information of voltages concerning my Liverpool project, but now I am in a position where I can make measures with those critical voltages. Hopefully I can test my new baby next Sunday with my band. Regards Harry Bluetone