Problem with Einstein

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ruben_veil

ruben_veil

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:cry: What's wrong to my Einstein 50 head??? :cry:

The past week I received my einstein from Germany... I sent the amp cause it make a noise like and freq modulator with and without my guitar plugged in... And this problem is solved... But my amp doesn't sound with the power and rage of before... I put the master 1 or 2 in max volume, but it doesn't sound brutal like before...

What's the problem? It could be a Bias problem?? My Einstein S/N: 002/106. Delivery Note: 002/106-01LS. Customer Code: 105

Sorry for my bad english and thanks for all!!!


PD: Could anybody upload to youtube any video of Biasing an Einstein??
 
You can find biasing instructions on the official website - go "tech"
 
Ok, thanks!!

Another Quest... When I received my amp, and I put it on, it smells a bit like a resistance burned...is it normal? This days, it smells less (a bit only)...The amp sound... but it don't sound well I think... BIAS problem? Another problem??

Thanks!
 
Diezels do smell - like any other tubeamp. The transformers and the tolex glue the most.
 
Before it was repaired, it wasn't smell, but ok....

Then, if my Einstein don't sound with the gain of before... is it probably that is a adjusting BIAS problem???


Thanks a lot for your patience!!!!
 
You know, in 95% its the tubes, although I doubt its the power tubes in your case. Cold biased tubes sound lifeless and "cold". Hot biased tubes sound more muddy.

I'd play around with V5 and V1 (which is closest to the input jack). Swap them (nothing in the loop) to hear if it get any better. Checking the bias from time to time can't be wrong either.

Good luck.
 
Hot biased (if hot means more idle current) do not exibit more crossover distrortion as crossover distortion is created when on half of the sine wave is given the other tube to operate the other half of the wave. By biasing it hotter you actually bias the tube nearer to class A operation point that exibits no crossover distortion. Cold bias will cause nasty crossover distrortion....

About your amp:
Tube amps smell???Thats a good one...

Jokes besides, if it really smells like a burned resistor that is absolutely NOT normal! I would think of a screen resistor on the power tubes first. Maybe a dying power tube caused it's death and you operate your amp only with an odd number of functioning tubes. Are you able to measure B+ voltage on the sockets to verify my theory? If you have no clue keep your hands off and bring it to a qualified tech...

Best, Stefan
 
How to measure the voltage? I've a multimeter, and I know a bit of electronic only.. Changing the El34 for 2 news is a good try? (My Einstein is the 50 watt version)
 
can you post a pic of the internals, esp. the power tube sockets?

yeah, I've got the crossver dist. flipped., but (to a certain degree) all tube amps smell. They don't smell burnt of course.

B+ normally is around 480V in Diezels. You need to open the amp, upside down and read off PIN 4 and PIN 3 of your powertube-sockets. DMM set to 1000V DC, red to PIN, black to chassis.

Don't do this if you are unexpoerienced.
 
Ok.. later I'll probe to change the tubes 1 and 5, and will see BIAS. I'll take pics and a video.

Thanks!!!
 
I have a new question... In the instructions located in the backpanel, it says that I've got to remove the "outer" fuse, but I've only inner fuse...I understand that I've to remove the inner fuse, isn't it?

Yesterday I did a try, but in the multimeter the value was minimal (0.20 mA) When I moved the pot, the values changed, but in the moment return to the first value. Any suggestions?

Thanks a lot!!
 
Use inner then.

Set your Multimeter to Ampêres !!! 200mA DC A. You need to read 30mA +/- 20mA normally.
Make sure both probes have contact inside the amp. The red (to red hole) can be a bit difficult.
 
I had a problem several months ago that had to do with filter capacitors. See this thread:

viewtopic.php?f=14&t=24018

I posted an audio clip of the problem. If you are hearing similar problem, then it is probably the filter caps.

I replaced the caps and the problem disappeared.

later,

brian
 
Yes, my amp had the same problem with caps, and I sent the amp to warranty. My actual problem was that the amp don't have the power and rage of the begining...But yesterday I bought two new EL34 tubes, and I changed it... I was setting the BIAS to 65mA and all ok... My amp sounds fucking great now!!! I've changed V1 too.

Thanks for all to everybody... It was a simple tube problem :rock:
 
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