Attenuation vs. Yellow Jackets vs. Power Scaling Mod.

[pickinatit]

I have a Solarus.  I love the sweet tube over drive, but I've only heard it a couple of times since back in the day (early 70's, the last out door gigs I ever played thru it)  because I can't achieve it til the volume knob is at the ear splitting volume of between 6 & 7.  In an early thread, someone suggested attenuation.  In the process of looking into that, I've come across these two other possibilities for achieving tube overdrive without making my family or band mates deaf.

Yellow Jackets:
http://www.thdelectronics.com/products/yellow_jacket.htm

Anyone ever try these with their vintage Sunn tube amps?  Curious about the change in tone due to the EL84  vs. EL34 power tube.  I don't mind loseing a little bottom,  but I'd hate to loose that "chime" especially when playing clean.
This seems to be the most cost effective way to achieve my goal, but I really would value the opinion of others regarding tone issues.

Power Scaling: 
http://www.londonpower.com/pscaling.htm

A more permanent mod.  Reluctant to have an out-right mod. done to a classic, vintage amp.,  but it seems like a potentially logical solution especially if the claims regarding "unchanged tone" are true.  Any one have any knowledge/experience with these kits?  I'm not a DIY'er so the cost of the kit plus paying for installation would probably be equal or slightly more expensive then a good attenuator from what I've been able to research.
What are opinions on this type of mod. both from a technical standpoint, Tone stand point and just opinions regarding the wisdom of modifying a classic, vintage amp like my Sunn Solarus ?

Should I just stick with attenuation?

[EdBass]

I'm familiar with all of the methods you mentioned.
For what it's worth, these are my personal observations based on "hands on" experience.
An attenuator will accomplish the reduction in SPL you desire, and is probably the most cost effective method of simple volume reduction.
But... I've never heard an attenuator that didn't color the tone to some degree, mostly an unnatural compression effect. I don't think it's a bad tone, but it would be a different tone, albeit not radically different. Also, with an attenuator, you can significantly shorten tube life as you are still pounding the power tubes into full power saturation even at the lower SPL levels.

Yellow Jackets will change your tone completely. I personally like the tone of a wound up EL84 amp, and they are reasonably priced, but you will definitely change the whole tonal character of your Solarus.
I went to the link you posted, and I agree with the Vox analogy.

Power Scaling is one of the coolest innovations I've seen. It does in fact lower the output without significantly changing the tone characteristics. I have fairly extensive experience with Reeves Amplification's Power Scaled amps;
www.reevesamps.com
and they perform as described. Reeves has a licensing agreement with London Power, it's the real deal not just their interpretation of the technology. You can control the output all the way down to 1/2 a watt and with a little fiddling with the drive and gain controls still maintain the characteristics of the amp at full power. In fact, the Reeves Power Scaled amps don't have a standby; you just turn the Power Scaling knob all the way down.
Pretty cool stuff.

Here's one you didn't list, the good 'ole Variac. Kind of bulky to add to your gear and lug around if you gig a lot.

You can get tons of info/opinions/reviews of all of the above at;
www.thegearpage.net

[pickinatit]

I'm familiar with all of the methods you mentioned.
For what it's worth, these are my personal observations based on "hands on" experience.

Ed,  thanks for the commentary.  I was hoping that you in particular would chime in on this post.  I value your knowledgeable opinion and am particularly pleased that you have "hands on" experience with these options.

You seem to be pretty positive regarding the Power scaling technology. It does sound to me from what I've read about it (and I've read reviews etc. other then just the one I've posted) like it might be the closest to ideal solution.  But also probably the most expensive, if I'm not mistaken.  I'm thinking that what I may do is try the "Yellow jackets" and see what I think of the EL84 tone.  I read another review somewhere that also said that, "yes, it definitely changed the tone of the amplifier (I forget what type of non-Sunn amp they were talking about now)  but that they LIKED the tone of the EL84's.  If I don't like it I can always go back to the EL34's and do the Power scaling thing later.  That's my thinking right now.

I still would welcome additional opinions, insights, suggestions, experiences any others have had with these options.

I'll be giving this more thought before I do anything though.  I'm not in any rush.  I've had my Solarus for about fourty years now and of all my Sunn amps SHE ain't going anywhere.  Besides I don't play guitar in my band these days, I play bass.

Thanks again Ed.

[EdBass]

I agree, the Yellow Jackets are reasonable, "plug 'n play", and like I posted, I'm one of those that like the sound of a nice EL84 amp.
Some EL84's can get a little "fizzy" sounding, I'm referring to that Brian May-esque EL84 tone.
Pure tubey bliss... 

I don't want to divert your thread, but since you are playing bass and we're discussing tone... 
Lookey what I just got!
To put the big Reeves into scale, that's a 2000S cab it's sitting on.

[pickinatit]

I don't want to divert your thread, but since you are playing bass and we're discussing tone... 
Lookey what I just got!
To put the big Reeves into scale, that's a 2000S cab it's sitting on.

Wow, nice rig!!  Just out of curiosity though,  why didn't you install the Power Scaling Tech. into a 2000S ?  (Not that I can't appreciate a new "toy" like that Reeves.)   That's also a beautiful cab. That's recovered and re-done grill cloth, right?

[EdBass]

The Reeves is much more powerful with substantially more headroom than my 2000S's are, and I generally like a big clean tone for bass. I personally don't have use for Power Scaling, that Reeves just has a standard master volume, and it's mostly wide open.
It's also a two channel amp, normal and bright, and I bridge them and roll down the master which allows me to overdrive the output stage to get some good grind if the mood strikes me.
Depending on the style of music, I usually use the Reeves or a 200S for gigging, with one 215S cab loaded with EVM 15L's. It's plenty for stage volume, I mic the 200S or use the DI on the Reeves into the PA for FOH, and it's one heck of a lot easier to schlep around than those 2000S cabs.
My 2000S rigs rarely leave my shop. That picture was taken at a talkbass.com GTG that I brought a full 2000S rig and the Reeves head to, mostly because a lot of the younger folks there had never seen a 2000S rig in person, and because the old dudes enjoyed the trip down memory lane.
We were blowing out drop ceiling tiles for most of the afternoon, it reminded me of the days when I thought I needed that kind of fire power to gig.
I let technology and sound reinforcement systems do the SPL "heavy lifting" for me now days. I think it's called "older and wiser"! 
I did play an outdoor venue a couple of years ago with two 2000S heads and four cabinets. The guitar player showed up at load in with his 112 combo in his hand, looked at my rig, shook his head and walked to his side of the stage without saying anything. The sound man had me almost out of the mix completely, and let's just say my bandmates were less than happy with my stage volume.
Kind of silly in this day and age, but I must admit, it was kinda fun.
That cab is re-grilled, but that's the original tolex.
By the way, I wouldn't carve up one of my 2000S's to modify it, IMO another reason for you to use the Yellow Jackets that I failed to mention earlier.

[wilddeath]

wow these yellow jackets seem pretty cool.  i have an old ampeg gemini II and have never really been happy with the tone.  Once only with a gibson sonex i could get a Marshally sounding tone from it. But never one for that sound.   Im going to pick up a pair and see what they do for it.

[pickinatit]

The Reeves is much more powerful with substantially more headroom than my 2000S's are, and I generally like a big clean tone for bass. I personally don't have use for Power Scaling, that Reeves just has a standard master volume, and it's mostly wide open.
It's also a two channel amp, normal and bright, and I bridge them and roll down the master which allows me to overdrive the output stage to get some good grind if the mood strikes me.

So, your Reeves amp doesn't have the power scaling feature?  Am I understanding you right?  Makes sense.  I wouldn't really see the need in a bass rig.  I play pretty much clean most of the time. 

By the way, I wouldn't carve up one of my 2000S's to modify it, IMO another reason for you to use the Yellow Jackets that I failed to mention earlier.

I'm glad you spoke up about this.  I would be reluctant to make a mod. to my Solarus.  I'll probably try the Yellow Jackets and see how that sounds. 

[EdBass]

The Reeves is much more powerful with substantially more headroom than my 2000S's are, and I generally like a big clean tone for bass. I personally don't have use for Power Scaling, that Reeves just has a standard master volume, and it's mostly wide open.
It's also a two channel amp, normal and bright, and I bridge them and roll down the master which allows me to overdrive the output stage to get some good grind if the mood strikes me.

So, your Reeves amp doesn't have the power scaling feature?  Am I understanding you right?  Makes sense.  I wouldn't really see the need in a bass rig.  I play pretty much clean most of the time. 

By the way, I wouldn't carve up one of my 2000S's to modify it, IMO another reason for you to use the Yellow Jackets that I failed to mention earlier.

I'm glad you spoke up about this.  I would be reluctant to make a mod. to my Solarus.  I'll probably try the Yellow Jackets and see how that sounds. 

Correct, the Reeves Custom 225 in the pic does not have Power Scaling.
I suppose they could Power Scale it, but Reeves doesn't offer the Power Scaling option on any amps bigger than 60 watts.
60 watts is a bunch for an all tube guitar amp, I think they figure that anyone using 100+ watt guitar amps probably isn't real interested in being quiet.
I think that particular Reeves pushes 240ish watts on the 8 ohm tap, as with all handbuilt amps there is some fluctuation. The reason they called the amp the Custom 225 is because none of them will fall under 225 watts at any load.
You can Power Scale a vintage amp without hacking, making the mod completely reversable. But, it takes some real creative mounting fabrication, and personally I wouldn't use it anyway.

[pickinatit]

I'm trying to determine which "Yellow Jackets" I should order. 
Is the Solarus a  "grid bias"  or  "cathode bias" amp ?

[Soundmasterg]

Adjustable Grid bias.

I vote for power scaling myself, but not to hack up a vintage amp unless its a basket case already.

greg