Maintenance noob with Diezel VH4 tube problems

[Tallgeese]

Hello everyone,

As the title says I have a Diezel VH4 that is acting weird. I blew a fuse and have these as replacements

http://www.frys.com/product/5850373?sit ... IN_RSLT_PG

But now when I power on my amplifier (power and standby) my tubes get hot FAST and they glow very red all the way down the shaft in the center.

Do I just need to replace the tubes? And on that note I've been reading that with Diezels I need to have it biased EVERY time I get new power tubes? If so does anyone know of someone that can work on it in Seattle WA?

One last question on the new tubes, does anyone have any experience with Tung Sol tubes in their Diezel? I've heard a lot of great things about them.

Its a lot of questions I know, but I've had my VH4 for 5 years now and I've never had ANY problems with it and it was my first tube amplifier. My VH4 has been SO good to me that I have no idea what I'm doing when she breaks down!

 

[bananaladonpcp]

KT77s and stay away from Tung Sols unless you want crappy tubes that go microphonic or aren't worth a damn. Has it been a while since you last changed your tubes? If it has then you need to do that. Blowing a fuse usually means you have a bad tube but could also mean some other things as well. But if it's glowing more then usual and if it blows a fuse again then you deff need to change them. And if you've never changed those tubes in 5 years then you are about 4 years over due and need to change them ASAP as you have been living with serious sub-par tone. In my opinion the best KT77's around right now are made by Gold Lion but the Ruby (JJ made ruby tested) KT77s are what Peter is putting in his amps out the door right now.

Oh, Yes you MUST re-bias your amp every time you change your power tubes. If you don't know how you should bring it to a shop and have it done. I can't help you out with your area though. Sorry about that... If you're friends with the tech you can ask him to show you what to do and you can do it yourself. I check and adjust mine every month. But I have a Herbert with external biasing so it's stupid easy to adjust it.

 

[Peter Diezel]

Hello everyone,

As the title says I have a Diezel VH4 that is acting weird. I blew a fuse and have these as replacements

http://www.frys.com/product/5850373?sit ... IN_RSLT_PG

But now when I power on my amplifier (power and standby) my tubes get hot FAST and they glow very red all the way down the shaft in the center.

Do I just need to replace the tubes? And on that note I've been reading that with Diezels I need to have it biased EVERY time I get new power tubes? If so does anyone know of someone that can work on it in Seattle WA?

One last question on the new tubes, does anyone have any experience with Tung Sol tubes in their Diezel? I've heard a lot of great things about them.

Its a lot of questions I know, but I've had my VH4 for 5 years now and I've never had ANY problems with it and it was my first tube amplifier. My VH4 has been SO good to me that I have no idea what I'm doing when she breaks down!

Welcome to the board

Your tech should also check the fuses inside the amp on the big PCB.
For the tube fault fuses I would recommend ceramic ones You can
get from Mouser.

I attached a PDF with our recommend tubes You can get from
Ruby Tubes / Magic Parts. If You would like to be save with
reliability I would go with a sextet of KT77-JJ. Bias should be
70 mA each PAIR , 35mA each TUBE.

Cheers,
Peter

 

[i.ak]

All users have good and bad things to say about any tube brand. They all are piece of crap from reliability point of view. Even a new tube can fail in few weeks. Im currently using TungSols in all of my amps and they sound good - Yet, the best sounding tube I have not met. Honestly, I have never seen any functioning tube to ruin an amps tone, but definitely EQing is needed to certain extend when changing tubes - But this applies to the same brand in some occasions as well.

Biasing is always a must when power tubes are changed - Even if same brand and type are used. If you do not know how to do it, go to tech and follow his work. Very likely next time you can do it by yourself, but remember that there are lethal voltages involved - No full-body protective rubber clothing needed though, unless you want to make it a different kind of experience.

 

[Peter Diezel]

The Tung Sol is a very good preamp tube but
couldn´t use it for V1 and V2 concerning
micro phonics.

 

[Tallgeese]

Thanks so much for all the replies especially Peter, can't think of anything more reassuring than getting a reply from you!

I'm family friends with Michael Soldano and he has worked on it a couple of times just as regular maintenance, whenever we see him he just asks me to bring it by. Although thinking about it I'm not sure if hes ever swapped the power tubes, I know hes changed the pre amp tubes and hes probably adjusted the bias. I wont be taking it to him for this repair though, I don't really ask for repair favors because he is such a nice/busy guy.

I was mostly wondering about the Tung Sol because somewhere in the back of my head I was hoping that a $4500 amplifier would sound the same with an $80 matched quartet. But I was expecting to spend Genalex money anyway, and I've been wanting to round out some of the variables in my tone with new tubes so I think I'll try the KT77's.

I've been wanting to learn more about amplifiers and their repair/maintenance seeing as how I own something I can't replace! Between running a business from home, moving, music it doesn't leave a lot of wiggle room, I was an electronics engineer so learning shouldn't be a problem once I actually take the first step.

Again thanks so much for the replies!

 

[bananaladonpcp]

You can find the Ruby JJ KT77's for around 22 bucks a piece. The gold lions are alittle bit more. around 30 a piece i have found them for. Good luck!