Should I have more cleans

[jrusto]

I just finished a 5E3 build and am some what perplexed because I barely get clean sounds out of it. With the volume at 1.5 if I dig even slightly hard I get distortion. Below 1.5 I get next to nothing. I realized when I built it that it did not have much head room but I feel that I do not have any head room. Is this normal. Additionally, the tone control seems very unsensitive. Moving from max to min I get some difference in tone but not like I am used to with other amps. Is this normal.

While I dd not check voltages on the pins of the tubes, I did check a few voltages as outlined in Tube Depots build guide and found a couple high voltages. The voltage at the 25uf cap that goes to pin 8 of the power tubes is at 500v and supposed to be at 460. The voltage at the cap going to pins 8 and 3 of V1 is 3.5v rather than 1.5v as suggested by the TubeDepot document. If these things are not normal where would I look to fix them.

Thanks in advanced for your help.

[MWJB]

"The voltage at the 25uf cap that goes to pin 8 of the power tubes is at 500v and supposed to be at 460." The voltage at this cap should be <25vdc (twenty five volts). You might have a bad ground at the other end of that cap & resistor and the tube is drawing next to no current?

3.5vdc at pin 3&8 of V1 equates to 2mA per side, if you have a 12AX7 in V1 then something is very wrong, but if you have a 12AY7 in V1 then things might be OK. What voltages do you get at the 2x100K resistors that feed V1 pins 1 & 6, measure on the eyelets on the board, at each end of the inverted "V" and at the middle.

[jrusto]

Sorry. I mistakenly said the 25uf cap and I should have said the B+ voltage. And the other voltage was with a 12ay7. I will take additional readings tonight.

Thanks

[MWJB]

Either way, there shouldn't be 500vdc anywhere in that amp, if all the tubes are drawing appropriate current.

[EETStudent]

The symptons you mentioned are not totally uncommon. In my experience, they can be pretty typical. Your choice of transformers and speaker will have a lot to do with that early breakup.

Like MWJB mentioned, 500VDC anywhere is ridiculously high for that amp. What schematic are you referring to? Stock 5E3s wont come anywhere close to 460V. What PT is being used?

As for the tone control, sounds about right to me. The tone control reaches its brightest at about 6 or 7 on the dial, from there on it gets rounder and more overdriven.

Definitely investigate those voltages. Depending on the PT, a stock 5E3 should get between 350-400V on a good day.

[jmaf]

A customer of mine has a les paul clone with some Seymour Duncan pickups, their output is so high they'll saturate the cleanest of my amplifiers.... It's like the input expects 75mV and that thing pumps out a volt(?).

If it isn't your guitar, and if you're not using a high gain(I.E long plate) 12ax7's in place of the 12ay7, then there's something wrong with it.

The 820 ohm cathode resistor on the 12ay7 is for the two triodes, shared. If you build it with just one triode you gotta double that resistor, that will limit gain as well. If you find it still is too hot, remove the 25x25 capacitor off gain stage two, and you may even increase the 1k5 cathode resistor to 2k2 or 3k3.

Vintage amp rebuilds do break up easier with newer pickups and high gain tubes, perhaps all you need is a tweak.

[Bruce / Mission Amps]

Supposed to be 460vdc?
In my opinion, these voltages are absurd and so far off that it is nearly impossible to help diagnose this... you need to sit down and describe more accurately what you really have there.
For example; are you trying to build a 5E3 with your own spare parts and using a reissue power transformer for a Super Reverb with a GZ34/5AR4 rectifier tube? etc.