Diezel VH4 50W or 25W, is this possible?

Dany M

New member
Hi all,

I'm a long time Diezel VH4 fan, and I have an interesting question that might be cool for other people too, so I'll post it here.

I recently moved to an appartment where 100 Watts of Diezel power is just a little to much, so I'm looking for an option to keep the volume down. I know there are a lot of loadboxes available (I'm currently testing a Groove Tubes SEII), but I would like to know if it's possible to run my VH4 on just 2 or 1 power amp tubes (EL34 for the moment), thus changing it into a 50W or 25W head.
Perhaps there is a way to put something in the remaining sockets? I remember I read a thread some years ago on the HC forum where someone did this...

25 Watts of tube amp power is in my opinion for most of the cases still loud enough, so I don't mind if it's tricky to change it back.

Thanks a lot in advance.

grtz,
Dany
 
hey i saw a lot of people pulling 2 tubes out of their sockets in a 100watt marshall and they set the impedience from 16ohm down to 8ohm. i'm in the same situation as you are. but i didn't pull any tube. i think one of the biggest volume comes from the cab you're playin maybe you should just try a 1x12 instead of a 4x12(if you play a 4x12). the watts of an amp is maybe the main part of the sound you're hearing out of your amp. i think 100watts down to 50watts is about 3% loss of volume. but you can distort the poweramptubes a bit earlier. but it will be loud as hell too.

knut
 
^^ +1. Dude, the loudness will not dramatically decrease at all when you pull tubes. I think you may be better off with a THD hotplate or a similar device.
 
Another vote for using a smaller cab. You might be surprised how good a nice 1x12 can sound.

To significantly reduce the volume you'd have to turn the Diezel into a 10W amp (half the volume of a 100W amp). That just isn't feasible so using an attenuator is your best bet. The master volumes on Diezels are really good so you could use an attenuator to drop a little volume (instead of attenuating a lot) and then set the master volume low.

Another option is to use an attenuator in dummy load mode (THD Hotplate for example) and run its line-out into a separate poweramp. I find this works quite well and gives you precise control over volume. It's not the same as running the amp without attenuation but it does give some pretty sweet tones.
 
I had my VH4 running down to 4 watts by installing four Smicz Tad power tubes. These were 6AK6 one watt power tubes with a special base made for the voltage to match the Diezel's. I used it out on jobs at four watts and was plenty loud enough.
I also tried two Tads, but the cleans suffered a bit.

If you cannot find these tubes, you may try the THD Yellowjackets. These are EL-84 power tubes with a special base for adapting these tubes to the Diezel's larger power tube sockets. No biasing is needed either. One pair of YJ's will run the amp at about 18 watts. The tone will be slightly different from the regular power tubes but you will get the volume down. This also allows you to turn each dial up further to get more sound out of the amp.

These methods worked very well for me for a number of years using my VH4. Ultimately, the Herbert came out and I now use that and an Einstein 50 combo.

I have tried both the Tads and the YJ's in the Einstein but the volume suffers and being in a 6 piece band, I need all the power that the amp has, so I just use it the regular way now.

Good luck.
 
Thanks everyone for the replies, I' ll try the 6AK6 tubes.
Looks like the perfect solution for me.

I found a web-link (http://www.londonpower.com/faq.htm) about pulling out tubes, but apparently removing tubes affects the sound a bit, so not really the perfect solution.

I also looked into a hotplate, but I don't like the fact they do some EQ'ing to compensate for the level drop.

By the way, as a live sound engineer, I agree that low-wattage amps are perfect for most gigs. Most of the times when I have a band bringing in a AC30 into a concert hall, it's too loud and it messes up the FOH mix and stage balance. And that's only 30 Watts that need to be cranked...
Repeat after me kids; less is more! :)
If anyone wants to discuss stage volume with me, I'd be happy to speak for all those p.i.t.a. sound guys why we always want you to turn it down...

Anyway, thanks everyone for you help and kindness.

Cheers,
Dany
 
Follow-up:

yesterday I had a chat with my tube-amp-repair-guru (Geert from http://www.sonicart.be) and he told me that pulling out tubes, or using yellowjackets or similar kits are not ideal solutions for retaining your sound while dramatically lowering output level.

So he suggested me to look into this: http://www.londonpower.com/kits/psbox.htm
http://www.londonpower.com/kits/psk.htm

This looks almost to good to be true; a kit that allows you to reduce the level from 100% to 1% while completely retaining your beloved power amp distortion/compression! It works on the voltage of the tube plates and the bias (as far as I understand) so this gives you great sound, low volume and extended tube life as an extra.

Anyone with experiences on this Power scaling boxes?

Peter, I hope you' re not insulted by me modifying one of the best amplifiers on the planet?

grtz,
Dany
 
I've had an amp that came with built in Power Scaling. It was a Stephenson LJ10 (15W, 1x6V6+1xEL84 poweramp), I thought it sounded great but had a too loose feel for hard rock/metal so it had to go. I sold it to fund the Einstein combo.

While Power Scaling works great, I think the master volume on my Einstein works just as well. If the master volume on the VH4 is as good then I don't think Power Scaling would help much. Diezels don't seem to be amps that sound significantly better by cranking anyway.

There's a long thread about Power Scaling on The Gear Page so you might want to check that.

Regarding wattages, my experience has been that for heavier styles lower wattage amps don't seem to cut the mustard. Most of them seem to be voiced more towards blues/rock etc. and they don't quite have the same tight attack and punch bigger amps get. Aside from super low wattage amps (couple of watts or less) anything from 5W upwards can get painfully loud when cranked. I've found that more important than the wattage is how well the master volume works and in my experience Diezel is great in this respect.

For apartment use, you could consider using a smaller cab. Less speakers = slightly less volume. Believe me, I've tried pretty much all methods for getting great tube tone at home and Power Scaling and a good master volume are on the top of my list but even then they don't alleviate the problems of volume's effect on our hearing. That's a compromise you have to live with.

Another thing I found recently was that putting something (like a magazine) in front of the speakers can result in a more pleasing tone at low volume. It muffles the highs slightly (different from turning down treble or presence) and it's those frequencies that usually sound nastiest at low volume. This is an old trick, there are players who put tape on the front of their cab grille cloth, Weber even makes a "Beam Blocker" for this purpose. It kinda diffuses the highs more evenly. Its simple to try so give it a go too.
 
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