Liverpool build. HELP PLEASE.

[xjuddx]

Well after having built a few other amps I decided to to a crack at a liverpool. The layout I used had a few lines overlap so I used the ceriatone layout to fill in the gaps. When I fired everything up the tubes light up but there is no sound at all.

Things I have done:
Replaced the tubes with a different set out of another amp that I know works
Rechecked all my connections and noticed I missed 1 ground connection
Removed the impedance rotary switch and hard wired it for 8 ohm. The switch was removed because the wrong switch was sent and it couldn't be substituted.
I have traced all my wiring and I haven't seen anything that is off.

I really feel like I am missing something very obvious I will feel stupid for missing.

[xjuddx]

more photos

[cbass]

I only lookedd at the 1st pic.You need to go over your joints the black wire on the speaker jack is barely hanging on.

[cbass]

You don't have the cathodes pin3 on the two inside tubes connected to anything. It appears you have your bias resistor and bypass cap hooked to pin 4. Those brown heater wres look like a short waiting to happen you need to redo that. It can be a pain getting those 18ga stranded wires in there but they will fit

[xjuddx]

Hey, thanks for the help. The layout I had the those connected to 4 and not 3. I didnt even think about that until you mentioned it.

Unfortunately I got this chassis and transformers as a partially assembled kit (bare boards,, tube sockets and transformers mounted only) and the leads for the OT had already been cut so they were stretched tight to even get them there. I was planning on picking up some heavier gauge wire and splicing them together and heat shrinking it, i just wanted to get it running first.

The black on the input is in there pretty solid. It just looks lose because I didnt trim the excess wire off yet and it covers the view of the joint.

I am going to move those bias connections and lets see in we get some noise

Again, thank you

[xjuddx]

Nope, still no sound. Took the board out and found a connection that had come lose when I had soldered something up top and fixed that also

[cbass]

I'm sure someone will come along that knows alot more than I do. I've never built a Liverpool.

[xjuddx]

I really do appreciate the help. It seems like there are a lot more rocket and express builds then liverpools.

Seems like the layout on this site has a few mistakes unfortunately. The cathode / bias connection on the middle tubes would be #2 I found so far. Will make sure it gets updated when i am done

[BLT]

Could you post the layout and do you have a schematic? I see on the one layout I have that they did not hook up the inner EL84 cathodes. Instead they are going to heaters. The schematic looks correct, the layout looks wrong. I'd also like to see the power supply. I'm going to throw in this revised layout.

[drew]

Have you checked voltages?

[xjuddx]

Those are the same schematics and layouts I was using. The layout also splits the grounds on the bias and runs one side down to the same points as the mains which could cause a lot of noise so I connected the ground across the 2 resistors similar to the schematic and rand the ground away from the mains.

I havent checked voltages yet. I took my meter out when I started the project and it seems to have gone missing so I am picking up a new one tomorrow.

[gktamps]

1st; post new photos so to show your corrected wiring.

The bias circuit wiring is shown correctly on the schematic. The layout does not appear correct; R23 and R24 share the same ground point. That faint orange line that looks like a connection under the board doesn't actually appear to connect at the other end, certainly not on the PT grounding point. I suspect it's an artifact created during drawing or rendering, and not intended to show a ground connection for R23, which should have had a jumper from its turret to the adjacent turret of R24.

BTW, I think it's always a good idea to give the AC line ground its own screw connection, shared with no other ground wiring, and ground the PT with its own screw immediately adjacent.

[M Fowler]

Red wire not connect to pin 3 of the two middle EL84's. Pin 3 is cathode each pair of EL84's has it's own cathode resistor and bypass cap. The layout red wire stops short of reaching pin 3 but that is where it goes.


Looks like that yellow wire from OT to the speaker jack would touch the barrel of the speaker plug.

Pins 4&5 of EL84's are the filaments.

Pin 7 is plates from OT blue & brown wires.


Screens are Pin 9.

Pin 2 is grids.

Make sure your tail resistor R11 has good connection to presence pot.

[didit]

Those are the same schematics and layouts I was using.

That layout is confusing and even outright wrong, as you’ve noted. Schematic, which seems correct, is your best hope so go careful through step-wise from rectifier forward and ground up. More photos as others suggested already might help us help. Different angles to shed into shadows, particularly the power board.

I was planning on picking up some heavier gauge wire and splicing them together and heat shrinking it, i just wanted to get it running first.

You might consider putting isolated 2 tab terminal strip above that bias ground bolt and terminate the transformer filaments, then splice to the sockets from there. Can’t see if the transformer has CT for that secondary, but reasonable spot for hum reducing DC or ground.

Best .. Ian

[BLT]

I also noticed on the bad layout that only one side of the power supply bias is grounded. A couple of suggestions once you get some sound. You might want to use a shielded wire on the input, grounded at the jack. Some people will go as far as using shielded wire going from the volume pot to pin 2 on V1. Also, when you're soldering thru the top of the turret, fill up the hole. It just brings up more questions down the road. You're probably going to want to dress the heater wires against the chassis, and keep the signal wires away from the heaters as much as possible without adding much more wire to the run. It's also a good idea to keep signal wire and heater wires 90 degrees to each other where they cross. As most of the guys here say, lead dress is critical in these amps. Other than that I think voltage readings may tell us a great deal.