Diezel Herbert having some seemingly major issues.

[zakmetal]

Hey guys,
So I purchased a Herbert off of eBay about a month ago. After G.A.S.ing over one for nearly 8 years I finally got one. It came in an AWESOME flight case which I got both for $2600, crazy deal, although the channel 2 led is out . BUT, now I am questioning if everything is ok with this amp. So here is the story.

Got the amp in, plugged it in and it sounded GREAT!!! Left the positive feedback on eBay, played it for days. It was GREAT!
So then I had a wedding gig out in butt f*ck Kentucky which turned out to be outside, at night (they didn't mention that when they booked us). I thought everything would be ok, but before too long there was some dew/condensation build up on the amp. I should have covered it up but didn't even think about it. But the amp worked fine that night, no problems what so ever.
Brought the amp home, plugged it in the next day and got little to no guitar signal output and a massive hum/hiss and very high pitched feedback. Pissed that the dew probably caused an issue, the only thing I knew to do was to replace the tubes. So, I got out some old tubes and swapped ALL the tubes out. It had Mesa EL34 and Tung-Sol 12AX7's from the seller, I only had Mesa 6L6GC's and Mesa 12AX7's. Rebiased the amp (no external bias points on this one ) and plugged it back in and IT WORKED!! I was very releaved.
Took it to band practice 2 weeks later (only the 2nd time I have taken it out of my house) and it did the same thing!! Massive hiss/hum, little to no guitar signal, and very high pitched feedback.

The only thing I can figure is that it could still be a tube issue considering I put old tubes in it and it probably had old tubes when I received it. So I am taking it to a local amp tech and letting him check it out. I also plan to order a full new set of tubes from dougs tubes.

So, does anyone have any idea what the hell is going on? Pappa? Anyone? Anyone have any experience with dougs tubes, in particular his 6 preamp tube cocktail? What is the best tube combo for the most angelic cleans (maybe EL34's) and the most aggressive gain (6L6?, or KT88's?). As per papa diezel's recommendations I would like to avoid 6550's.

Thanks in advance to anyone who can guide a new Herbert owner! and sorry for the long post.
-Zak-

ps Is there MASTER list of what to bias the Herbert to for specific tubes? i.e. EL34, 6L6GC, KT88, 6550, etc.

 

[PaulyPanacea]

sounds like a tube issue. 99% of the time thats all thats usually the problem. Some fresh tubes should cure your ailments...then hold on to your ass!!

 

[MARK2C]

It sounds more like a blown filter cap for the preamp supply than tubes.
Look at the two large 22uf/500V capacitors on the main circuit board to see
if they are leaking any yellow goo.

 

[duesentrieb]

ps Is there MASTER list of what to bias the Herbert to for specific tubes? i.e. EL34, 6L6GC, KT88, 6550, etc.

Diezel recommends to use only EL34BHT or Svet =C= biased to 60mA/pair.

 

[Peter Diezel]

If You need anything let me know at

peterdiezel (at) diezelamplification (dot) com

 

[zakmetal]

Ok so after the tech I took my amp to checked it out, he said that it looks to be a tube issue. I had been talking to Doug @ dougstubs.com about retubing my whole head because I just bought it used and wanted to start fresh.

This all being said I would like to say that I thought it was a tube issue in the beginning and just wanted to confirm it. I just bought the amp used and it was a little concerning to have it doing this right away. I contacted the seller and he said that he hadn't retubed it for YEARS. So I guess it was about time to change the tubes. Not to mention that the tubes I had put in it after having the initial problem where pretty old as well. By no means do I want to add to Sir Diezel's stress level by posting all this! I have already corresponded with him. I think it is an amazing thing that he checks the forum regularly and offers assistance to everyone. WHAT A GUY!

SO anyway, these are the tubes I am going to throw in the Herbie. Tell me what ya think.
Channel 1: Penta Labs KT88SC's.
Channel 2: RUBY EL34BHT's.
Channel 3: SED winged =C='s.

And for the preamp tubes:
1-Penta 12AT7
2-Ruby 12AX7AC5 HG
3-Ruby 12AX7AC5 HG+

Any Other Suggestions?

Thanks again guys for all the help!! I sincerely appreciate it.

-Zak-

ps. I would still like to see a COMPLETE master list of each tube type and what the bias settings should be. I am willing to help if I can. Anybody interested?

 

[petereanima]

SO anyway, these are the tubes I am going to throw in the Herbie. Tell me what ya think.
Channel 1: Penta Labs KT88SC's.
Channel 2: RUBY EL34BHT's.
Channel 3: SED winged =C='s.

hi!

this wont work the way you posted it, as ALL power tubes are always in the circuit - they are not assigned to specific channels only!

you can of course mix them, but it will be the mix of the tubes on all channels - only some of the preamp-tubes are assigned to specific channels only!

 

[RJF]

As said, all 6 power tubes power all three channels. This seems to be a common misconception with the Herbert.

For me it's KT88's throughout. As far as preamp tubes, I would just put back in what comes stock in the Herbert.

 

[HerbieBoogie]

Ok so after the tech I took my amp to checked it out, he said that it looks to be a tube issue. I had been talking to Doug @ dougstubs.com about retubing my whole head because I just bought it used and wanted to start fresh.

This all being said I would like to say that I thought it was a tube issue in the beginning and just wanted to confirm it. I just bought the amp used and it was a little concerning to have it doing this right away. I contacted the seller and he said that he hadn't retubed it for YEARS. So I guess it was about time to change the tubes. Not to mention that the tubes I had put in it after having the initial problem where pretty old as well. By no means do I want to add to Sir Diezel's stress level by posting all this! I have already corresponded with him. I think it is an amazing thing that he checks the forum regularly and offers assistance to everyone. WHAT A GUY!

SO anyway, these are the tubes I am going to throw in the Herbie. Tell me what ya think.
Channel 1: Penta Labs KT88SC's.
Channel 2: RUBY EL34BHT's.
Channel 3: SED winged =C='s.

And for the preamp tubes:
1-Penta 12AT7
2-Ruby 12AX7AC5 HG
3-Ruby 12AX7AC5 HG+

Any Other Suggestions?

Thanks again guys for all the help!! I sincerely appreciate it.

-Zak-

ps. I would still like to see a COMPLETE master list of each tube type and what the bias settings should be. I am willing to help if I can. Anybody interested?

that is quite a specific mix.

Good luck and remember if your gonna try some 6500's or kt88 to make sure you find a way to cool herbie. those tubes get incredibly hot and some people have problems with them if you dont properly cool herbie!