spritzer

He was trying to push some half baked ES-1 (aren't they all) earlier this month. Claiming that the normal input was a preout or some other such nonsense.

Here is the full glory of the SP umbilicals. At least there is some teflon insulation on these wires or probably tefzel. The amps are all wired with PVC...

One thing Al (and all of those that own SP amps) check the umbilical cables on the inside. I just did and one wire was loose with plenty of them dangerously close to shorting out. Ohh, and it's built VD style with a rubber hose and some loose wires inside. One of them didn't even have anything to secure the techflex... To open them up you just screw the back part of the plug. You need a bit of force but once you are inside the black clamp can be opened up with some pliers and it just pops off the cable.

As an added bonus, build it with all the faults Mikhail did and you have the extra fun of fixing it regularly.

That makes my 2005 Passat 2.0FSI seem puny by comparison...

That's what you get when you don't (can't?) calculate the what the caps should really be and follow the schematic blindly.

Is there any way to remove the bottom of the chassis, Al? That would mean a much better view of the whole PSU.

Ari is correct. Shame on me but I'm so used to connecting ECC83's up at 12.6v that I forgot about the CT's role... As for using the 6SN7's instead of 6CG7, it should sound better due to the better voltage specs for some 6SN7's but you have to watch the filament current.

They have the same pinout, the 6CG7 and the ECC83, ECC99 etc. minus the heater CT. I also had this saved, presumably from HF: The full list might be in order:

The horror!!!!

The different tubes used is certainly a part in the amps downfall. With the Extreme for instance there were some rather power hungry tubes used which when coupled with the crap build quality led to damage. The heater supplies were undersized and so were the HV lines. Most manufacturers build and design their units to fit with one certain tube. All the operational parameters match said tube and the filament supply works just for it. Now that doesn't mean you can't put in some other tube to try. There are many close relatives with different pin configurations or slightly more/less gain etc. which should work just fine. On top of that you have the same basic tube design but with a different heater voltage. The ES-1 for instance was designed around the ECC81 and the 6CG7, both of which are easy to substitute for. Some of those cheap adapters are identical to the SP units. My ES-1 lacks the ECC-1 unit so I checked and a 6CG7-6SN7 adapter is the same thing.

Detailed pics of the amp would certainly help, especially of the front panel biasing setup, what's inside those plastic cans in the PSU and of the various components on the PCB's. For instance as you can see in Elephas's amp, the coupling caps are serial connected to get the rather odd 50nf value but I could never see what the value is from the pics of your unit. If this is different then it would be great to document it.

If you think that's bad, how do you think being down in the mines all day is/was. It was a good show though...

The UK version is very good.

I have too many toys...

Here and here. Compare them to this and this (the original Stax schematic)...

Hahahaha... that just made my day. The bottom line is, in a circuit like the ES-1 is very easy to use different tubes. Now whether it is a good idea is debateable but I don't think it is a great idea to run some of these tubes on a +400v PSU. When I modified the circuit for the A11 I would only use ECC99's in the second stage due to their high voltage capability and it's only running at +350v. I stuck a ECC83 in the first stage to get the high gain but I've yet to try how it behaves at full power.

Damn this sucks. If you can open the amp and PSU up and post some Hi-Q pictures then we might see what's gone wrong. Marc, isn't it about time the whole family got together for some soldering fun?

I'm sure you can get the P-1 cheaper through the deputy services then AQ2. Almost anything is cheaper then AQ2...

....

TC sounds right for a Sony deck. I have a TC-355 sitting on a shelf and I've never even plugged it in...

I'd take caps in the signal path over the danger of exploding Li-Ion batteries. Just imagine how crappy the other RSA amps are (such as the cRaptor) as they have coupling caps and cheap electrolytic output caps.

Ahhh so you were lacking the force of a nordic thunder god to push the connector home...

It's my old ECR400 cable.

I wouldn't mess with the socket personally, I would rather measure the socket/pins and make short jumper leads. Make sure they are properly insulated since there is a lot of voltage coming from those transformers.