Marshall Valvestate 8040 mods?

[philbinator1]

Hey guys,

I'm trying out a 8040 valvestate from a mate as my possible new practice amp, it's got good volume still
has that brittle 'solid state' sound even if I roll the contour knob all the way back to get some mids.  I think
I've been spoilt with tubes   

Any ideas to make it sound a but tubier/less hollow?  Mods etc?

Oh and my mate is getting my Line 6 spider II 30 watter with Floorboard  as a swap...whaddaya all think
of that?  Fair swap?


Cheers
Phil

[petemoore]

I'm trying out a 8040 valvestate from a mate as my possible new practice amp, it's got good volume still
has that brittle 'solid state' sound even if I roll the contour knob all the way back to get some mids.
  This amp:
1  Sounds great
2  Does well
3  Is a bit brittle
4  Really kickaz metal sound man
  depending on when, who, where, with what.
  I'm not even sure what the amp is, if it's like the combo amp used on lapsteel last night. It was 6' up in back against a wall so it had a mostly direct shot to the recievers. Clean was good and clean, dry perhaps, the dist-O sound had all the ingredients except perhaps the bass...being in the audience of course afforded no chance to change tweekings..which was done probably @ 3 or 4' out away from the speaker, I was 15' farther out.
  The reason I mentioned 6' up and back-walled is because that makes a big difference, though it probably did nothing for taking the SS sound out of an SS amp [not a bother, I thought it sounded very impressive, not a possibility anyway..the speaker/amp thing is what it is, speaker being the easy thing to improve on, amp being...the format it is].
  @@Rate they can have nice sound, and Valvestate is known for collecting 'brittle' comments...maybe I just have biased rememberances of when I used them.
   I think I've been spoilt with tubes Tends to crop up when the tubes are working good. 
  Any ideas to make it sound a but tubier/less hollow?
  This is a stompbox forum, not a cabinet/speaker design place, we do talk about pickups so that might warrant discussion.
  Mods etc?
  I think they're quite flexibly EQ'd. The preamp is where the non-linear behaviour is created, what makes it sound 'V-state', with the whether or nots involving high Voltages, whether or not you can improve [guiseppe says odds aren't that great] leads me to discussion outside the chassis. I'd say EQ but I think there's good frequency controls already there.
  OT
  If it's a combo try a big cabinet with nice speakers.
  Try different guitars.
  Other than that the suggested route is to work with it, get cool tones [it does cool tones...just have to work with it] you like or transcend to a different format.

Oh and my mate is getting my Line 6 spider II 30 watter with Floorboard  as a swap...whaddaya all think
of that?  Fair swap?
  I think I'd prefer the VS because it sounded more like an analog channel was available [I think there is one on it], it just sounds 'fast', the L6 amps I've tried just seemed 'slow' perhaps due to the reverb but also the distortion just seemed like it was slaggin'. Neither one wanted to produce tube tone I get [defined bass/smooth treble].
  Unless the VS happens to have a 'slave amp' input [inputs post preamp..directly into the output amp].
  I would start on a 2x LM3886 overture power supply as a 1rst way to re-work the preamp. That way you have your big 'ol clean monster amplifier [each one gets a 12'' reasonably effecient speaker working strong] to try beating what exactly you have there.
  One of these, a nice infinite baffle speaker cabinet, no preamp, pedals [except reverb and distortion]...you may find it easier to work on [all can be done at like <40vdc, excepting of course the mains wiring..fairly simple to wire, test, finish test, UNPLUG, heat shrink].
  At least that way you're building your stuff up. Fiddling with the VS preamp...yukk compared to your construction which was designed to be fiddled with. It also eliminates the possibility of ending up -1VS.
  These hot rod SS amps are hot rodded with great tech design, the afford great flexibility to begin with...if the variables don't happen to include 'tube sound' that you prefer, another format is what I'd consider.
  Another thing that you may get an opportunity to test is to use the VS preamp output into a tube output amplifier..just to see what that does, this totally blows the ''all in one'' aspect of the amp though.
  So...not much as far as SB's to use with VS, or VS internal mods, 'improved' speaker cabinet is always nice thing to have around when trying to 'open up' the sound of amplifiers, especially useful for increasing bass dimension and perhaps punching up the mids more smoothly.
  Sell it and you'll never know what it could have done, ie the gutiar/pickups/playing style afforded with this amp can be plain stellar, or not what you're looking for...bending it...it's already very flexible as it can get.
  Someone else of course may offer a different approach and have figured out the magic that the extensive design process that went into the amp missed [but I doubt it].

[anchovie]

If this is built like the heads or larger combos in the 8*** series, it will be impossible to get the pcb out of the chassis to work on without completely destroying the standoffs. You'll then find that nowhere sells exactly the same standoffs and have to improvise.

I used to have the head and thought that sounded brittle too. The clipping is all from diodes, there's a single tube gain stage/cathode follower after the clipping section to try and smooth things out.

There are other people who think the VS series sound awesome. I'd say if you don't like how it sounds now then you never will, so you should keep the Line 6.

[Ice-9]

I used to own an 8240 marshall, which i think had one of the best sounding distortions i have had in a ss power amp (valve preamp).

anyway a good place to start with anymods is with the schematic, and this is available over at the "Dr Tubes" site I could post you the link here if that is allowed ??

[philbinator1]

Wow thanks for that massive reply Pete, I surely appreciate your time and typing!  I didn't get some of it, partly because I
haven't looked into it that in-depth - obviously you have experience on the subject.  The 'outside' influences you talked about;
I have a amp stand, so I would get some extra volume.  My pickups are great, EMG 81/85 in bridge/neck respectively, so
no worries from me there.  I think the cabinet is better than the line 6, less 'boxey' sounding, more boomy.

James - thanks for the info.  Will try it again tomorrow at volume, flatmates are asleep at the moment    Wasn't impressed
with the eq section at all, didn't seem like the various controls actually did much (treble sound really muffled at low levels, bass
wasn't really there and the Contour control should have been a mid control i think).  Having said that though it does metal pretty
good like Pete said, and lots of volume for noisey drummers.   Anyway yeah if I don't like it after more testing tomorrow, i'll
call off the swap and just save for a 20ish watt tube jobbie.  Pity though, seems like an amp with good potential.  Funny that
I have these opinions now, I used to own a 8280 years ago and thought it was the best amp evaaaar.

Ice 9 - hold off on the schem thanks, i'll see how my Metal-fest goes tomorrow...god (or should that be satan) help any flatmate
who want a nice nana-nap      haha.

Thanks fellas.  

[jonfoote]

i had an 8080, it was fine till you turned it up to gig levels and then you found there was no bass comming out of the thing.

[petemoore]

  A quick, unfiltered boil down of opinion:
1  Cabinet: A large infinite baffle cabinet will afford better bass extension and definition. Seems like the highs may smooth out but I guess that's a perception thing. Whatever the case, this is worth investigating if the tests thus far are through a 'partial shell' combo cabinet.
2  Speaker: the voice coil[s and cone choice makes a big difference too, how cranked is the speaker [bass especially] = the excursion distance = sweet spot of speaker. In a sealed enclosure this can also translate to compressed air behind the speaker and compression sound.
3  Amp: The VS power supply and amplifier is estimated as technically very good. These days a high performance amplifier is pretty much 1 thumbnail sized chip, the power supply is where the big hunk of fixin's and expenses reside. Getting an amp which has very low and very high frequency response and adequate power is like an 'addendum' to aquiring a speaker/cab and power supply needed to complete the system...enough about amps..
4  Output tube "whatever you wanna call 'ems": Air pressure transduced to 'electron pressure' [I warned there might be junk phrasings and incoherent texts here] inside a vaccum tube compressing a volume of contained air behind a speaker...causeing ''movements'' in the power supply. whew..that said.. SS amps try these kinds of tricks in the preamp. The reasonably designed output amplifier of SS amplifier gets nowhere near it's peak output at any time.
...By 'call ems' I mean 'em things a tube does to frequency response, gain, in milli or nano second duration sweeps, in sympathetic time constants related to coil/cone excursion beats, air pressures etc etc etc.
 4...lol, it's what we end up with that leads us to what we we're getting, and sometimes more clearly defines what we still want.
5 I've owned really nice things and not known them so well, later learning more about what they actually were.
 Check out the LM3886 if you wanna play with mains Vs', I got a blown subwoofer gonkulation of 1000W category, plenty of scorched mosfets and excellent 4700uf capacitors, free. Difficult pulls [the amp was built like diamond tough]...excellent performance. This made the "high performance" [impressive/I like 'em] amplifier power supply and filtering a relatively casual financial affair, the transformer from somewhere helped too, I bought a torroidal for the LM3886 chips. 40w of wide frequency response per 12'' speaker affords about all my 12'' speaker will tolerate, watt-wise, very clean amplifier otherwise.
 Yupp.. instead of fiddling with the high tech valvestate, you can make even a small chipamp, experiment with speakers and preamps and fuzzboxes.
 That way you don't have to tear up your high tech VS amplification circuit/system, which IME leaves little room for improvement over itself.
 I will know more: "afterwords''.
 You mentioned a 20w tube jobby, it's an option I would explore..with the right speaker/cab and boost or distorter...different sound is pretty much guaranteed. Also a whole new approach...the VS is pretty easy to tell what it does, it's all a switch or knob turn away, getting that kind of flexibility out of a new and simple platform is comparitively complicated. Good news is: almost, if not every bit of this complication can be very nicely ironed out '@ 9Vdc.

[philbinator1]

*strokes chin thoughtfully*....Yes, yes I thought so.      Wish I could understand that stuff man, I'm afraid I'm
of the simpler persuasion at present.   

Seriously though.  I tried it again today at considerable volume...no doubt that it absolutely blows the Line 6
out of the water for that (volume).  And with it cranked, the eq changed heaps, and the treble increased along
with the bass (not so much though).  Is that a thing that SS amps do?  Because when I crank up the Line 6, the
treble becomes unbearable and it has to be completely re-eq'd to compensate for the volume. 

Anyway I may end up swapping it, I think I might build some kind of tube preamp/booster to put in front of it or
though the FX loop.  Any suggestions?