what's your opinion on half power switch? tone drain?should I mod an amp for it?

everdrone

New member
what's your opinion on half power switch? tone drain?should I mod an amp for it? prolly expensive mod. I have one on my Marshall JCM900 4500, not too bad. it definitely changes the characteristic of the tone since it takes out some more of the bass by default. does the half power switch sound good on other amps like the new Orange th100, Mesa Boogie Rectifier and Roadster, Tiny Terror, and countless others? is it worth buying an awesome 100 watt amp like an Ampeg V4 even though I could buy an Ampeg V2, and then add a half power switch? is that like "having two amps" like the ads read? one for practice and turn switch to full power for gigs? People say to just pull tubes but on other forums amp techs and gurus say dont just pull tubes as it hurts your amp. I dunno, prolly the purist thing is to just buy one amp for each needed use, a 50 watter for practice and a 100 watter for shows? some say a half power switch add on is expensive and sucks out the lows and does a weird EQ curve to the high frequencies ??? ??? ???
 
Re: what's your opinion on half power switch? tone drain?should I mod an amp for it?

Why bother? the actual volume difference between 50 and 100 watts is negligible. If your 100 watter is too loud a 50 watter will be too loud too.

In general im not a fan of half power switches. They can be cool for getting a different texture or tone out of an amp but the power scaling unless it goes way way down really doesnt do much.


Are you after power amp distortion? If so get one of the many small tube amps on the market today. But I find that lots of times guys get caught up chasing power tube distortion only to be disappointed with it. For me most amps are too compressed and i dont like how they feel or respond once ive pushed it hard enough to get lots of power tube distortion. But thats me it might be your thing and you might really dig it.
 
Re: what's your opinion on half power switch? tone drain?should I mod an amp for it?

ive not heard a half power switch that ive liked the sound of. In my experience it still sounds better on full power with the volume knob dropped by a touch.
 
Re: what's your opinion on half power switch? tone drain?should I mod an amp for it?

It was OK on my JCM 900 dual reverb. I just didn't use it much because I was playing in a very loud band when I had it, and I wanted the headroom.

It was very good on my Boogie Mk. III combo. And I think it is very good on my Express 5/25 as well.

The VPR on my JCM 2000 TSL122 was decent as well. Good for low volumes in the house, but nothing I'd make a record or play a gig with.

I don't know if I would modify an amp to have one...but I would always welcome it as a feature if it already came on an amp. It's easy enough to ignore.

As for V4 vs. V2, the V2 is a hair easier on the back, and a hair more filthy at reasonable volume. It is my favorite amp I've played, in terms of pure tone, though they can easily be too loud for a venue. I'd get a V4 if I wanted insane volume, maximum "thump," or reasonable cleanliness at moderate volumes. I'd get the V2 if I always used a lot of natural amp distortion. Master volume (and master volume converted) V4's don't sound as good IMO, so maybe a half power setting wouldn't either
 
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Re: what's your opinion on half power switch? tone drain?should I mod an amp for it?

If you have a 100 watt amp. you can change it to 50 watts by removing the 2 outside power tubes. It will sound the same, just 50 watts. You will need to correct the ohmage on the back of the amp. If you were running the 100 watts at 8 ohms, the 50 watts will need to be corrected to 4 ohms on the amp. You can still run it through your 8 ohm cabinet, but at 4 ohms. You don't need a half switch.
 
A Weber attenuator probably would make much more sense than trying to modify an existing amp.

There are many ways to reduce an amp's power output. You can drop the voltage for the power amp portion of the circuit (called VVR by some). Switching out a power tube or two works in some cases. In some cathode biased amps you can swap in lower power tubes like 6V6s in place of 6L6s (but please do NOT assume that's safe in your amp!).

A really good amp tech might be able to work his magic in your amp, but an attenuator is much cheaper.

Cheers,
Chip
 
Re: what's your opinion on half power switch? tone drain?should I mod an amp for it?

I don't use the half power switch on my Marshall 2553 Jubilee. I prefer the tone on high power, plus Jubilees aren't particularly loud for their wattage and they sound OK with the volume backed off anyway.
 
Re: what's your opinion on half power switch? tone drain?should I mod an amp for it?

thanks guys for the insights. Great stuff, I learned a lot! :) :)

I definitely would only want to change the headroom so that I hear the amp's distortion at a lower volume. I think I would want to do this through a switch that pulls out two tubes basically, but I am not sure how that alters the tone since the amp was designed for full volume pure tone, and a lesser wattage amp is designed for just that. i.e. I dont think an amp designer of a 100 watter amp and a 50 watter amp would say that the 100 watter sounds just the same as a 50 watter if you pull two tubes and use a different ohm to go to the speakers.

itsabass - those v2/v4s sound great, I have been a fan of QOSTA/kyuss for years as my top 5 fav band, Josh digs those and they sound great on his albums.

http://www.drtube.com/schematics/marshall/jcm900.pdf is my amps schematic which says

8. Output Mode Switch
Switches the amplifier from high to low power
output. The “low” setting configures the output
stage to “triode” operation, which gives half the
rated output (i.e. 25 Watts on 50 Watts models - or
50 Watts on 100 Watt models). The “high” power
position gives “pentode” operation for the full
rated output.

this does not mean I need to switch the ohms, right? for some switches When in half power you really need to change the speaker from the 8 to the 4 ohm output because taking a pair of tubes offline effectly doubles the ohm rating. I dont think this is the case here cause it really is pentode/triode changing the way the tubes work, right?

people say slightly more mids and a slightly more compressed feeling in triode mode. It really chops off the top and bottom and leaves nothing but mids...


there is like 10 different types of switches. I am skeptical about the hotplate attenuator types - I remember some people fry their amps doing that cranked volume route. like a tweed switch which drops the voltage going to the power tubes, this will alter the tone.
 
Re: what's your opinion on half power switch? tone drain?should I mod an amp for it?

I thought power scaling was a big feature on those Orange Thunderverbs? I guess I read that wrong.

Anyway, adding a half-power mod to any good / classic amp seems like a bad idea to me. You're spending money to make something that was worth money, worth less money. You follow me?

If you like the tone of an amp, buy it. If you don't, don't. Don't buy gear because you like how it sounded on somebody else's record and then throw money at it until it sounds right.

Josh Homme uses V4's cranked to blow out stadiums...has been since Kyuss opened for Metallica...for us average joes a cranked V4 is just a noise complaint waiting to happen.

and the 3db volume difference and negligible difference in tone means the half power switch is just...well...redundant, extra stuff to have on the amp. Maybe if it cut from 100 to 25 watts you would notice it...but I've been lugging my 68 Bassman to band practices for a decade and keeping up with 100w Marshalls and Mesas no problem...
 
Re: what's your opinion on half power switch? tone drain?should I mod an amp for it?

I tried the half power switch on my Splawn for a gig or two, and it sounds way better on the 100 watt setting.
 
Re: what's your opinion on half power switch? tone drain?should I mod an amp for it?

I thought power scaling was a big feature on those Orange Thunderverbs? I guess I read that wrong.

Anyway, adding a half-power mod to any good / classic amp seems like a bad idea to me. You're spending money to make something that was worth money, worth less money. You follow me?

If you like the tone of an amp, buy it. If you don't, don't. Don't buy gear because you like how it sounded on somebody else's record and then throw money at it until it sounds right.

Josh Homme uses V4's cranked to blow out stadiums...has been since Kyuss opened for Metallica...for us average joes a cranked V4 is just a noise complaint waiting to happen.

and the 3db volume difference and negligible difference in tone means the half power switch is just...well...redundant, extra stuff to have on the amp. Maybe if it cut from 100 to 25 watts you would notice it...but I've been lugging my 68 Bassman to band practices for a decade and keeping up with 100w Marshalls and Mesas no problem...

thanks for the response! the thunderverb is great, I should prolly just leave it at that...but next amp I plan to get in 12 months or so is anorange tiny terror combo that has a half volume switch on it, and also I was considering trading in my marshall jcm900 for an ampeg v4 or v2.... so ya I have the amp bug. sounds like the ampeg v4 is awesome for stadiums and bass which is cool flexibility, not so sure about a switch that takes out two tubes though...dont want to hurt the tone and it would be going through my orange 212 closed back cab. :scratchch prolly not a good idea to install a switch into the ampeg v4 thanks for the insights :approve:

ya, not worried about 3db volume change, just about distortion from amp breakup at lower volumes. I had a jcm800 2203 about 15 years ago and hated it cause the distortion on my half stack was so lousy - all I heard was the pedal I was running through it really, and it was very very noisy even with a noisegate.

here is a nice article that sums things up about volume and wattage and switches and hotplates: http://www.guitarplayer.com/article/5-things-about-reducing-amp-volume/147573
 
Re: what's your opinion on half power switch? tone drain?should I mod an amp for it?

The VPR (virtual power reduction) switch on my JCM2000 TSL100 is awesome! It cuts the power down from 100w to 25w so you can turn the amp up and get the good tone out of it without the overpowering 100w. Great for practicing and small gigs. It also keeps even tube wear. I'm not sure if modding an amp to have a half power switch achieves this same quality, but when it comes on an amp like this it is great. I'm sure the combo version has one too. You may want to look into purchasing an amp with something like this already on it.
 
Re: what's your opinion on half power switch? tone drain?should I mod an amp for it?

lol thanks for all the insights guys, keep em comin, I have the amp bug and more info and choices is the only cure for me!! :approve::friday: that new marshall switch sounds pretty cool, I wonder how the orange tiny terror switch is?

I tried the half power switch on my Splawn for a gig or two, and it sounds way better on the 100 watt setting.
edit/my error: cool, I see you have the 100 watter and that it neuters your tone and you are indicating that just turning volume to liking is your preference. You must be setting your ohm as described otherwise it will really alter your tone per the splawn website and other users on forums I read up on pulling out 2 of the power tubes and they like that setting. Thanks for your insights :)

splawn website says:

7. What does the half power switch do?
The half power switch on the 100 watt amps disconnects the the two outside power tubes. You will need to set your ohm selector on the amp to half of what you speaker cab ohm load is.
On the 50 or 40 watt amps its a Pentode/Triode switch, you do not have to change the ohm load when using this function.
 
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Re: what's your opinion on half power switch? tone drain?should I mod an amp for it?

If you are going to do any mods you would benefit a lot more from power scaling/VVR

It's not a big mod an works far better.
 
Re: what's your opinion on half power switch? tone drain?should I mod an amp for it?

itsabass - those v2/v4s sound great, I have been a fan of QOSTA/kyuss for years as my top 5 fav band, Josh digs those and they sound great on his albums.

That ****er is probably why they have gone up in price so much in the past 10 years. You used to be able to get great, early V4 heads all day for $200 to $400 from the local classified rag. I've owned a few, and a V2. I paid $500 for my last V4, for the full half stack. Ended up selling it and the V2, though I still have the V4 half stack that has been in my family since new in 1975.
 
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Re: what's your opinion on half power switch? tone drain?should I mod an amp for it?

I have a VHT Special 6 Ultra that has both a low/high power (triode/pentode) switch and variable wattage which I assume is the same as power scaling.

The two have totally different effects:

The wattage control goes from 0.5-6 watts, and doesn't have that much effect on the overall tone or volume, it just reduces clean headroom. It seems almost like a drive control in reverse - the more you turn it down, the more distorted the sound gets. However, at very low settings it does seem to suck some of the low end out of the tone, and can get a bit fizzy if the volume is up high.

The triode/pentode switch has a very noticeable effect on the sound. As well as reducing the volume, triode mode is much darker/duller sounding. I can't say I use it that much, but there are a few things it suits quite well, eg if I want really mellow cleans, or don't want a 12-string to sound too bright and jangly.
 
Re: what's your opinion on half power switch? tone drain?should I mod an amp for it?

I have twoo similar amps with different power reduction switches.

My genz benz el diablo head cuts 2 power tubes out of the circuit. I don't have to play with the impedence either. I checked the bias when it was in 50w mode and the bias was WAY different than full power.
I thought it was a bit rounder sounding, though ultimately not much difference and definitely not worth adding

My 60w combo has a pentode/triode switch. This has a drastic change in both the sound and feel of the amp. Triode mode is warmer than pentode. It has the same amount of bass and mids in either mode, they just have a more squishy sag in triode mode. The mids seem thicker too.
I really like both modes. I use triode more though. It helps get rid of the thinness that amps get at bed room volumes.
most guys like this mode better.
In fact, i want to put a triode switch on the head. I would use it more often
i could get 25w /50 w triode or 50w/100w pentode.



Triode gets me more of a 70's hard rock sound whereas pentode seems more
modern.
 
Re: what's your opinion on half power switch? tone drain?should I mod an amp for it?

what's your opinion on half power switch? tone drain?should I mod an amp for it? prolly expensive mod. I have one on my Marshall JCM900 4500, not too bad. it definitely changes the characteristic of the tone since it takes out some more of the bass by default. does the half power switch sound good on other amps like the new Orange th100, Mesa Boogie Rectifier and Roadster, Tiny Terror, and countless others? is it worth buying an awesome 100 watt amp like an Ampeg V4 even though I could buy an Ampeg V2, and then add a half power switch? is that like "having two amps" like the ads read? one for practice and turn switch to full power for gigs? People say to just pull tubes but on other forums amp techs and gurus say dont just pull tubes as it hurts your amp. I dunno, prolly the purist thing is to just buy one amp for each needed use, a 50 watter for practice and a 100 watter for shows? some say a half power switch add on is expensive and sucks out the lows and does a weird EQ curve to the high frequencies ??? ??? ???

It for sure affects tone, but not necessarily in a bad way. I have a JCM 900 SL-X 2100. At 100 watts its a little brighter and crunchier sounding. At 50 watts it's warmer, not necessarily bassier. Its hard to tell if it breaks up more because I'm pushing the preamp gain hard. The volume difference is negligible. The only difference I hear is when it's load load, like past half. At 100 watt mode it "knocks" in the mids a little bit more.
 
Re: what's your opinion on half power switch? tone drain?should I mod an amp for it?

hmm... amazing how much yall know that I am not aware of, and collective knowledge is mind blowing here, awesome forum, cheers :beerchug:

did not know about power scaling / vvr --- that stuff is mind blowing hard to wrap my head around all these switches, I will prolly research this further, I see amp kits available when I google this, makes me wonder what exactly my thunderverb has. bottom line is I overthink stuff sometimes, thunderverb is super killer, dumping money in my backup is prolly not the best idea ;)

the ampeg v2 sounds like a killer option, I see one on ebay http://www.ebay.com/itm/Ampeg-V2-Tu...916?pt=LH_DefaultDomain_0&hash=item3f185d761c but I like the master volume ones, prolly super loud, cheers :)

non master volume ampeg v4 seem to go around $700 but are incredibly loud, prolly not a good idea to mod em I dont uderstand what mods are good for what I am trying to do for downtuned fuzz heaviness chunk ..here is one on ebay http://www.ebay.com/itm/Ampeg-V2-Tu...916?pt=LH_DefaultDomain_0&hash=item3f185d761c
 
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