ProSoundWeb Community

Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => SR Forum Archives => LAB Lounge FUD Forum Archive => Topic started by: Brendon Bass on August 03, 2007, 03:31:31 pm

Title: attenuators for tube amps
Post by: Brendon Bass on August 03, 2007, 03:31:31 pm
I have an old (1976) 100W Marshall MKII head that, needless to say, is way too loud for most of the situations I use it in.  I wanted to be able to get that cranked tube sound, so I purchased a Marshall Powerbrake off of Ebay.  It works fine for a while, but then will randomly cut my amp off for a few seconds and then cut back on again.  It seems to me that it may be overheating.  A few people I talked to said they don't recommend using attenuators, but I'm hoping I can get mine examined and the problem can be fixed.  Any suggestions?
Title: Re: attenuators for tube amps
Post by: Tom faderjockey Brandis on August 03, 2007, 03:33:45 pm
Before the powers that be get to you, you better go and put your full name in your profile. They'll lock your post if you don't. It's stated in the rules.

Tom
Title: Re: attenuators for tube amps
Post by: Tom faderjockey Brandis on August 03, 2007, 03:34:36 pm
Sorry, I thought I PM'd you. Oh, well.
Title: Re: attenuators for tube amps
Post by: Mark Coward on August 03, 2007, 05:07:07 pm
If the sound is cutting out like that with the Powerbrake, I'd definitely not use it anymore until you get it checked out. Not sure about that unit, but most of these type units are designed for a specific load, 4 ohm, 8 ohm etc. which your amp & speakers need to match. You don't want to fry the output tubes or transformers.

The Ted Weber stuff is pretty highly recommended, he has some based on passive resistors and also some with an actual speaker motor assembly http://www.tedweber.com/atten.htm

I'd suggest that you check out the ampage guitar amp forum http://music-electronics-forum.com/forumdisplay.php?f=10
Title: Re: attenuators for tube amps
Post by: Byron Marsh on August 03, 2007, 05:23:54 pm
Brendon,
About a year and a half ago I was looking for an attenuator for my amp(s).  I read several places where there were some problems with the PowerBrake so I looked elsewhere.  Of course, other people gave positively glowing reviews.  At least one of them said they had a problem with overheating, but I don't remember any actually saying that it cut out completely.

I ended up going with the Weber Mass 100w because it generally got good reviews and has a reactive load as opposed to a purely resistive load.  I have used it on my 50w Marshall head and my Fender SuperSonic head and it sounded great on both.  I have occasionally found seen them on eBay.  http://www.tedweber.com/

Don't know if this helps.
B-)
Title: Re: attenuators for tube amps
Post by: Mark Meagher on August 04, 2007, 11:06:18 am
+1 on the WeberMass.



Title: Re: attenuators for tube amps
Post by: David Buckley on August 04, 2007, 04:25:41 pm
Definite -1 on the powerbrake; as a load they alegedly look quite nasty, and some amps disaprove.

My recommendation goes to the THD HotPlate.

Title: Re: attenuators for tube amps
Post by: Bob Leonard on August 04, 2007, 04:27:44 pm
The Marshall Power Brake is junk and the Weber is not to far behind it. The best attenuators made are from THD, or the Gibson branded THD Power Stealth. Your choice, they cost the same, but are light years ahead of anything else on the market and do the job perfectly.

http://www.thdelectronics.com/products/hotplate.htm

http://www.gibson.com/Products/Amplifiers/Gibson%20Amplifier s/Power%20Stealth/
Title: Re: attenuators for tube amps
Post by: Andy Peters on August 05, 2007, 12:03:46 pm
Brendon Bass wrote on Fri, 03 August 2007 12:31

I have an old (1976) 100W Marshall MKII head that, needless to say, is way too loud for most of the situations I use it in.


Ah, the electronic solution to the acoustic problem, which as we all know, never works.

Get a much smaller amplifer.  Spend $400 on a recent-vintage Fender Deluxe, or look around for an old Ampeg Reverberocket or something.  Lighter and not all that loud and sounds better than the Marshall.

-a
Title: Re: attenuators for tube amps
Post by: Marsellus Fariss on August 05, 2007, 02:55:02 pm
Bob Leonard wrote on Sat, 04 August 2007 15:27

The Marshall Power Brake is junk and the Weber is not to far behind it. The best attenuators made are from THD, or the Gibson branded THD Power Stealth. Your choice, they cost the same, but are light years ahead of anything else on the market and do the job perfectly.

http://www.thdelectronics.com/products/hotplate.htm

  http://www.gibson.com/Products/Amplifiers/Gibson%20Amplifier s/Power%20Stealth/





I completely disagree with you. I've had the THD Hotplate and I have the Webber Mini Mass and they sound pretty much the same. There's some slight variations but it's not night and day. I don't see spending over twice as much on the THD. Both will change your tone somewhat especially if you attenuate a great amount. The left hand side of the dial is pretty much uselsess from 12:00 counterclockwise to off. It adds a buzzing fizzy sound depending on what amp your using. I find attenuators to be very amp specific.



Title: Re: attenuators for tube amps
Post by: Bob Leonard on August 05, 2007, 05:26:42 pm
Marsellus Fariss wrote on Sun, 05 August 2007 14:55

Bob Leonard wrote on Sat, 04 August 2007 15:27

The Marshall Power Brake is junk and the Weber is not to far behind it. The best attenuators made are from THD, or the Gibson branded THD Power Stealth. Your choice, they cost the same, but are light years ahead of anything else on the market and do the job perfectly.

http://www.thdelectronics.com/products/hotplate.htm

   http://www.gibson.com/Products/Amplifiers/Gibson%20Amplifier s/Power%20Stealth/





I completely disagree with you. I've had the THD Hotplate and I have the Webber Mini Mass and they sound pretty much the same. There's some slight variations but it's not night and day. I don't see spending over twice as much on the THD. Both will change your tone somewhat especially if you attenuate a great amount. The left hand side of the dial is pretty much uselsess from 12:00 counterclockwise to off. It adds a buzzing fizzy sound depending on what amp your using. I find attenuators to be very amp specific.






I've never had an issue with any of my Mesa Lonestars, Rect-O-Verbs, Nomads or Fender Super or Twin Reverbs. The tone stays unchanged or I wouldn't use it, period. Sounds more to me like you had a defective or abused unit.

Andy,
I agree with a lower powered amp but the new Fender shit sucks. ALL of it except maybe the Vibroverb, Vibro King or custom shop twin.
Title: Re: attenuators for tube amps
Post by: David Buckley on August 05, 2007, 07:08:08 pm
Since the OP uses a Marshall 100 top, I suppose I should note that Marshall have re-issued their old 20W amps, see a review here

I had one of the original heads, which I used with a standard 4x12 cab (model 1961, which I still have), and it was probably the best rock setup I ever had.  Many years on, I seriously regret selling that little baby.

These new amps are a shameful price though.  The original amps were made for mail order catalog shops, and didn't cost much money at all, they were intended for bedroom guitarists.

Title: Re: attenuators for tube amps
Post by: Minka Matikainen on August 06, 2007, 04:52:55 am
I agree with Andy that there is no good solution for this in electrical world, but...
...I've found those THD HotPlates to be decent for this kind of a work.

Better yet, you can actually change the seating for those tubes so that you can use smaller ones -> less power, still having the tubes driven to get that "sound".

Our guitarist did that and it has worked nicely for him.

The best solution would still be to find either a smaller amp which would be correct in terms of given SPL, or relocate the amp of the stage (although this would make you to be needing IEM's...)

My 2 cents

-Minka-
Title: Re: attenuators for tube amps
Post by: Steve Hurt on August 06, 2007, 08:40:49 am
THD makes a good attenuator.

Suggesting replacing a Marshall head with a Fender combo is like telling a Strat player to use a Les Paul, just not well thought out advice.  The Fender and the Marshall do not do the same tones.

A smaller marshall might work out if it;'s good one and not one of the solid state buzz boxes.

As far as all current Fender products sucking, I guess we'll have to agree to disagree.  I don't like the dirt channels on most of them but the clean channels are very usable on some of them.
Title: Re: attenuators for tube amps
Post by: Bob Leonard on August 06, 2007, 10:29:23 am
Steve Hurt wrote on Mon, 06 August 2007 08:40

THD makes a good attenuator.

Suggesting replacing a Marshall head with a Fender combo is like telling a Strat player to use a Les Paul, just not well thought out advice.  The Fender and the Marshall do not do the same tones.

A smaller marshall might work out if it;'s good one and not one of the solid state buzz boxes.

As far as all current Fender products sucking, I guess we'll have to agree to disagree.  I don't like the dirt channels on most of them but the clean channels are very usable on some of them.


Steve,
There's no denying the truth in your statements. The re-issue Marshalls are expensive for what you get, although the sound is vintage. 22 watts is about as small as a club amp can be and still be usable outside the studio. What seems to work out best are 40 and 50 watt TUBE combos or channel switching amps like the Mesa Nomads or Lonestars and smaller Marshalls or Bad Cats.

A good little amp for blues has always and will always be a Fender Deluxe reverb. The supposedly reissue has a good, not great, sound that is more than usable in most small to medium sized clubs and it's only 22 watts and cost $900. Pretty cheap.

The Fender clean sound from their current production line of amps is OK at best, but usable, and as you noted, they still don't make a decent channel switching amp.

On the Marshall side there isn't much that can recreate the sound of four 15 watt green back Celestions. But that doesn't mean the amp needs to be run with the power tubes saturated at 100 watts full output. That would be where THD comes in. Or, a good vintage TS-808 and a Ross compressor, or a Klon Centaur, will achieve the same effect at much lower volume.  Smile
Title: Re: attenuators for tube amps
Post by: David Buckley on August 06, 2007, 06:02:33 pm
Bob Leonard wrote on Tue, 07 August 2007 02:29

But that doesn't mean the amp needs to be run with the power tubes saturated at 100 watts full output.


Yes, it does.  There are 'master volume' amps that buzz at lower volumes, but there is little substitute for the full clip of a valve amp.

Doesn't mean the speakers need to be in the same acoustic space as the band though; put them offstage (dressing room, beer celler) anywhere, and mic it up and bring it back through the mons.

Or, you could do what I've done, which is admit that modern modeling boxes can get close enough to the classic tones to be usable (which means giving up 'perfection of tone'), and so much more convenient. This approach requires a mindset change on the part of the player though...

Title: Re: attenuators for tube amps
Post by: Steve Hurt on August 06, 2007, 06:20:12 pm
The Marshalls without the master volume sound better than the ones with it IMO.  One trick pony, but it's a heck of a trick!

fwiw, I believe that amp will work with 2 of the 4 power tubes pulled.  (pull either the middle 2 or the outside 2)

Check with you local amp doc for confirmation.

That would get you down to 50 watts so it would be a start.
Title: Re: attenuators for tube amps
Post by: Bob Leonard on August 07, 2007, 08:30:49 am
David Buckley wrote on Mon, 06 August 2007 18:02

Bob Leonard wrote on Tue, 07 August 2007 02:29

But that doesn't mean the amp needs to be run with the power tubes saturated at 100 watts full output.


Yes, it does.  There are 'master volume' amps that buzz at lower volumes, but there is little substitute for the full clip of a valve amp.

Doesn't mean the speakers need to be in the same acoustic space as the band though; put them offstage (dressing room, beer celler) anywhere, and mic it up and bring it back through the mons.

Or, you could do what I've done, which is admit that modern modeling boxes can get close enough to the classic tones to be usable (which means giving up 'perfection of tone'), and so much more convenient. This approach requires a mindset change on the part of the player though...




Have you ever actually heard a full stack running at 100 watts output? Rolling Eyes
Title: Re: attenuators for tube amps
Post by: David Buckley on August 07, 2007, 07:23:24 pm
Bob Leonard wrote on Wed, 08 August 2007 00:30

Have you ever actually heard a full stack running at 100 watts output? Rolling Eyes


I used to stand in front of a pair of them Very Happy  But hey, that was the punk era...

That was before I got a brain (and changed bands), and dropped to a single Marshall 100W (long gone), then a single 50W (which is also long gone) with one 4x12 (the one I still have).  Then I dropped to the 20W head.  We had a PA then Smile

Then I went all solid state, to a HH performer, which gave the sounds I wanted at more usable volumes.  It was also twin channel, so dirty / clean at the same level, which was never a real possibility for a classic Marshall.

These days I'm a lounge guitarist, so I have a Boss GX700, a stereo power amp, and the (modified) 4x12 in stereo.  We live in a detached house a fair way from neighbors, so from time to time mates come round and fancy making a noise, so the remaining valve amp I have (Carlsbro 60TC) comes out and I put the ear defenders on.

I must be getting old.  

My one wish would be that I could transport the GX700 back to my golden playing days, as it does everything just so much better than the copycats, memory men, colorsound pedals, the Schaller leslie simulator (not to mention the Farfisa rotary cab I used for a while) and the like of it.  Modern guitarists don't seem to appreciate just how much more choice they have then the guitarists of decades ago.

Edited to say:  And yes, Steve's right, you can yank two tubes from a 100W amp to make it a bit quieter.