Mesa/Boogie Simul 395 Stereo

Mesa/Boogie Simul 395 Stereo

serial#: S3684
year: 1992



2x 100 watt power amplifier
4x JJ ECC83S preamp tubes
8x JJ 6L6GC
2 separate sides - each with 2 independ channels
Class A or Simul Class (Class A + Class A/B at the same time)
Half drive and deep extend options
Variable bias installed
Hand made in the USA

page updated: Janury 14 2003

I think this is one of the few pieces of my gear that will most likely be changed last, if ever. A different preamp/speaker/guitar etc. is possible but at this point I can see no reason why I should want to buy a different power amp, unless it got stolen or a dozen tanks would drive over it (cause that's what it takes to break this thing). It is built to last, you can hook 8 speaker cabinets to this beast, produces 200 watts of the most beautiful tube power and it features so many options and switches that any type of poweramp sound I could think of is possible to create. And you can even switch between them when playing.

      of 395 channelsAs far as I know this is the only power amp (together with their Strategy 500) that has 2 fully programmable channels (to switch between them I use a Boss FS-5L), and even the left and right side can be programmed separately. Actually it has two totally separate power amps, one for left and one for right side. And each one has two channels. Which you can program by using the full/half power, normal/deep extend, Class A/Simul Class (Class A + Class A/B), volume and presence switches and knobs. I use the 2nd channel to create to the same sounds as channel one only with more volume for solo's. Without a doubt this (together with the Strategy 500) is the best and most versatile poweramp Mesa/Boogie ever built. No other poweramp has so many options and possibilities.

Before this poweramp, I owned a Marshall 8008 solid state 19" poweramp, capable of producing 2x 80 watt. But it didn't sound big, fat or loud, a 50 watt Marshall head sounds fatter and definitely much louder. When I traded my 8008 for this poweramp I could not believe the difference. It was like I was playing through a complete different amp. The sound was huge, massive, full, round & powerful and with a headroom which was unknown to me. The bottom end is so fat that my setup now can easily pass as a bassamp, especially when connected to a bass speaker cabinet. And it's not flabby or unfocused at all, which happens when you drive a 50 or 100 watt amp up.

Mesa amps have a fixed bias and run their tubes pretty cold. Although the tubes live longer that way, the soun could be better. I have had my amp modified and installed a bias trimpot for the tubes and run my amp pretty hot now. And it sure makes a difference. The overall sound is bigger and more dynamic. Clean sounds are a lot sweeter and less harsh, higher gain sounds have a nice compression to it and sound bolder. I highly recommend this modification to any Mesa owner as it will improve your tone a lot. 

Tubes of the Mesa/Boogie Simul 395 Stereo

I've played my stack (with 2 speaker cabinets) a few times at a volume level that was really totally outrageous but the sound only got better and never lost definition or tightness. Something that is impossible with a single 50 watt or 100 watt amp. Every tube amp has a sweet spot at which it sounds the best, and with this amp it is just slightly above your average level. So during rehearsals it sounds very good, but when performing live (and thus a bit louder) it sounds.... well you just gotta hear (and feel) it.


This power amp was built especially for the Mesa/Boogie Quad Preamp, so the combination sound amazing. The low end has a power and definition which is almost crazy. That's exactly the reason why I use a 200 watt power amp: capable of producing undistorted sound at any volume. I have a lot of low end in my guitar sound and to keep that tight you need a lot of power=headroom. That's exactly why bass amp's have so much power. So if I would have a 50 or 100 watt amplifier, the power would not be enough to create such a bass response that is not flabby, rough or distorted. But this one.... it is really over the top, the headroom is endless. It gaurantees me a clean, clear  and tight sound at any volume and that's exactly what I need and expect. Although it was designed to run multiple speaker cabinets, I've only hooked it in stereo to one Marshall 1960A 4x12" cabinet . But I'm looking forward to the day that I can hook this thing up to 4 (or more) cabinets......

      S I replaced the stock Mesa/Boogie tubes (Chinese) with an closely matched octed of (Tesla/)JJ 6L6GC's. I wanted either these or Svetlana's, but because the guy who builds Diezel amps recommended them (he uses these for all his amps, and they sound amazing) and the owner of Watford Valves prefered them as well for my type of use, I went with Tesla/JJ's. I really enjoy the improvement. The sound is more relaxed now, that's the best way to put it. Although my poweramp has an easy job to do - I mean 200 watts of tube power is a fucking lot of you only connect one 4x12" cabinet - I can now run it on half power without any "problems". When I had the chinese tubes, half power was not an option. The sound became very harsh and undefined. It was really painful to listen to. But now the sound just gets bigger when the powertubes are saturated. But because I still enjoy a huge amount of tight low end (all your bass are belong to us) in my sound, I run my poweramp at full power. As phase inverters I use JJ ECC83S. Nice clean and clear tone with a lot of headroom and seem to tame the presence a bit.

Related subjects

Mesa/Boogie Quad Preamp
Climax S# Preamp
Marshall 1960A speaker cabinet
19" Rack
Signal line

Mesa/Boogie Homepage
Eurotubes (JJ) Homepage
Watfordvalves Homepage

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