Diezel Herbert Dead

[bwgintegra]

Today has been a bad day for me, my Diezel Herbert Head died on me today. I turned the power on and let the tubes warm up for a few, then turned it
off standby. Was on the clean channel for about 10 sec and the amp lights flashed once and died. I checked the .5 Amp fuses and the middle one was in pieces. put a new fuse in and turned it back on and nothing. So I pulled the chasis, I found three different fuses inside the amp and checked all three good. It seems the input transformer has went bad. When I first got this amp I thought the transformer had a loud hum and posted here about it and was told it was normal. I have always still had a thought in my head that something wasn't right. The serial #1078 has external bias pots. I think it is a 2009. It has always sounded great and never had any issues with it until now. I am super bummed and hope to get it back running soon.

I have a strong electrical background and own a nice fluke meter. If anyone has any suggestions please let me know.

Thanks in advance for any help.

Does anyone know what kind of warranty Diezel has?

Where do I find a list of authorized repair list for Diezel amps?

Hope this doesn't cost me a fortune to fix!!!!!!!!!!

 

[RedB4Black]

If you bought it new, it has a 10 year warranty. If you bought it used, it doesn't have a warranty. Best to e-mail Peter direct.

 

[glip22]

Today has been a bad day for me, my Diezel Herbert Head died on me today. I turned the power on and let the tubes warm up for a few, then turned it
off standby. Was on the clean channel for about 10 sec and the amp lights flashed once and died. I checked the .5 Amp fuses and the middle one was in pieces. put a new fuse in and turned it back on and nothing. So I pulled the chasis, I found three different fuses inside the amp and checked all three good. It seems the input transformer has went bad. When I first got this amp I thought the transformer had a loud hum and posted here about it and was told it was normal. I have always still had a thought in my head that something wasn't right. The serial #1078 has external bias pots. I think it is a 2009. It has always sounded great and never had any issues with it until now. I am super bummed and hope to get it back running soon.

I have a strong electrical background and own a nice fluke meter. If anyone has any suggestions please let me know.

Thanks in advance for any help.

Does anyone know what kind of warranty Diezel has?

Where do I find a list of authorized repair list for Diezel amps?

Hope this doesn't cost me a fortune to fix!!!!!!!!!!

If your OT shorted you would still have power. I doubt it's that.

 

[Devilinside]

Sounds like a power tube shorted and smoked your fuse

 

[glip22]

Change your power tubes immediately. Before you do that measure your screen resistors.

 

[bwgintegra]

Just want to make this clear, the amp does absolutely nothing when power is on. No lights, no transformer noises, no nothing.
I think power is going in the primary side of the transformer but not putting anything out on the secondary. I will check to verify this, I still don't
understand why this would not cause a main fuse to blow and one of the output tubes fuses to blow to pieces.

 

[glpg80]

either you had a diode go down or a tube shorted.

and when 1 diode goes in a bridge setup, they all go! kind of like those kamakazi bastards in WWII.

the buzzing could have been accoustic noise from the diode(s) - you may have had a diode that tested fine but went. it is possible.

it is not the PT. transformer would have went before the fuse(s)

when was the last time the tubes were checked pre and post and the amplifier was biased properly or checked?

check all of your tubes one by one pre and power - if you do not know what to look for, then buy new ones or send it to a tech.

thats my bet - there may be other parts that need to be replaced depending on the power amp design safety circuit if it does indeed come out to the power tubes.

if you had a diode short (or anything in the linear power supply become deffective) other parts could be compromised and need to be serviced as well to make sure they have not become deffective.

 

[locoed]

If you can't fix it or figure it out,you can take it to Blitz amps in East Point,about an hour from you,he's worked on my Diezel,Bogner and many Mesa amps,he's the best around,and he's no newb to amp repair.Theres another cat in Royal Oak as well.
Dan at Blitz amps is the dude who built the first Naylor amp,and the company starting building them off his one design.\
He's a wizzard.

 

[bwgintegra]

Thanks Locoed for the great info.

Here is the update, Just found that one of the two 6.3 amp fuses that is inside the power cable plug was blown. So it must of had an overcurrent on the primary side on the incoming power. So now I have found two fuses blow, the 6.3 amp main and the .5 amp output tubes 2&5 pair. Guys what do you suggest I do before starting this amp up after I replace the main fuse. The amp has tube doctor el34b-str and tube doctor preamp tubes. I checked the bias on the amp when I received it and set all three sections to 60mA. I have a new quad of SED's and lots of preamp tubes.

 

[glip22]

Thanks Locoed for the great info.

Here is the update, Just found that one of the two 6.3 amp fuses that is inside the power cable plug was blown. So it must of had an overcurrent on the primary side on the incoming power. So now I have found two fuses blow, the 6.3 amp main and the .5 amp output tubes 2&5 pair. Guys what do you suggest I do before starting this amp up after I replace the main fuse. The amp has tube doctor el34b-str and tube doctor preamp tubes. I checked the bias on the amp when I received it and set all three sections to 60mA. I have a new quad of SED's and lots of preamp tubes.

I wouldn't use the power tubes that were in it when it happened. I would measure the screen grid resistors for good measure and do a good visual inspection before firing up. Chances are good one of the tubes arcd. Replace fuses and power tubes only and rebias. You should be good to go. I would get a voltage regulator if you do not have one.

 

[JerryP]

Change the power tubes and replace the bad fuses.
Jerry

 

[bwgintegra]

Just checked all of the 1K 5w resistors and all checked good. Will replace power tubes and rebias.

If you guys got any more thoughts let me know

Thanks for all the great help guys!!!

 

[JerryP]

More than likely it's just a shorted power tube.
Jerry

 

[bwgintegra]

Can you guys recommend what brand of preamp tubes you like in the Herbert

 

[Ventura]

Can you guys recommend what brand of preamp tubes you like in the Herbert

Chinese/Shuguang 12AX7B's will get you nicely sorted out. TAD7025S if you've got the moula.

As per all the requests - yes, a brand new quad of power tubes, new preamps to be on the safe side, make sure ALL fuses are in tact and connections are cleared of any debris from previously blown fuses.

And maybe a power conditioner pending on the voltage supply in your area. It's not the spikes that create the problem as much as it is the brown outs - lack of voltage and current. Either one is a bitch to tackle at the electronic level, but brown outs are pretty nasty as well.

Good luck!
V.

 

[glpg80]

Can you guys recommend what brand of preamp tubes you like in the Herbert

Chinese/Shuguang 12AX7B's will get you nicely sorted out. TAD7025S if you've got the moula.

As per all the requests - yes, a brand new quad of power tubes, new preamps to be on the safe side, make sure ALL fuses are in tact and connections are cleared of any debris from previously blown fuses.

And maybe a power conditioner pending on the voltage supply in your area. It's not the spikes that create the problem as much as it is the brown outs - lack of voltage and current. Either one is a bitch to tackle at the electronic level, but brown outs are pretty nasty as well.

Good luck!
V.

power conditioners will do nothing to solve the problems you stated it will fix. what you are looking for is a voltage regulator, which are much more expensive, and a power conditioner.

if i were running a $2000+ amplifier i would have both for sure. thats quite an investment to treat the same way as an over the shelf light bulb

 

[snowdog]

Can you guys recommend what brand of preamp tubes you like in the Herbert

You may want to visit the Diezel subforum here at Rig-Talk, where Peter Diezel himself recommends the exact tube to use, and where to get it serviced.

viewforum.php?f=14


As for your first reply where you say you think there is something not quite right about this head, I would take it to a tech to be looked at...If you can afford a Herbert you can probably afford a trip to the shop.

 

[Ventura]

Can you guys recommend what brand of preamp tubes you like in the Herbert

Chinese/Shuguang 12AX7B's will get you nicely sorted out. TAD7025S if you've got the moula.

As per all the requests - yes, a brand new quad of power tubes, new preamps to be on the safe side, make sure ALL fuses are in tact and connections are cleared of any debris from previously blown fuses.

And maybe a power conditioner pending on the voltage supply in your area. It's not the spikes that create the problem as much as it is the brown outs - lack of voltage and current. Either one is a bitch to tackle at the electronic level, but brown outs are pretty nasty as well.

Good luck!
V.

power conditioners will do nothing to solve the problems you stated it will fix. what you are looking for is a voltage regulator, which are much more expensive, and a power conditioner.

if i were running a $2000+ amplifier i would have both for sure. thats quite an investment to treat the same way as an over the shelf light bulb

Apologies - I use the term power conditioner in the same sense as voltage regulator and top model Furman line.

My bad.
V.

 

[glip22]

Well.

 

[johnnyjellybean]

You would be smart to check the tube sockets for any black marks or carbon traces because if a power tube indeed did arc over, there is a good chance it left a carbon trace and carbon traces conduct electricity.......... which means you'd short whatever new power tube you stuck in that socket. A pencil eraser will remove carbon traces.