HH 'Valve Sound Module'

[thermionic]

Hi,

I came across this thread whilst searching for something unrelated and thought it might interest some of you here. I'm not educated enough on this type of device to know whether this guy's reverse-engineered it well, but it might be worth a 'butchers: http://freestompboxes.org/viewtopic.php?f=13&t=92&start=20

J

 

[zebra50]

I've a couple of HH amps - one bass and one guitar - with valve sound functions on them. I guess they're the same or similar circuits. I could take some photos if anyone is interested.

To my ears the sound is not valve-like, but does distort...

 

[thermionic]

To my ears the sound is not valve-like, but does distort...

It'd be interesting to see the harmonics on an FFT. Is the distortion nice? If it's not valve-like, then I'm assuming it can't be too great...

J

 

[MagnetoSound]

One of my all-time favourite albums, Buzzcocks' Another Music In A Different Kitchen is a good example of the VS sound, as Pete Shelley and Steve Diggle both had VS Musicians at that time, if I remember rightly.

Not 'tubey', but quite characterful in an abrasive sort of way.

 

[abbey road d enfer]

It's just a common-source JFET stage. I bet they called it valve sound based on the then current assumption that FET's were similar to valves.

 

[s2udio]

Bit off topic................."H"arrison and "H"arrison (bros)... made some seriously good power amps.....the V series were excellent
I still own a couple of X1200,s...linear psu's ..very heavy and built like a brick **** house..super reliable.... under their last company name.....Harrison,Cambridge UK
nothing to do with the overseas brand of course...........!?
never to impressed with the guitar amps......but that tape echo was fun to watch........joe 90 style !

http://www.youtube.com/watch?v=1bNEV4NA1lE

 

[PRR]

> It's just a common-source JFET stage

Yes; but there's that other JFET with no obvious purpose, in-circuit for both positions of the "Valve Sound" switch.

The gate resistors suggest channel modulation in a way to give 2nd harmonic. But the amount seems to be 0.1% 2nd with much less higher-order, inaudible. Which moots the question of if the cap is 220n, 220p, or something else.

The common-source JFET stage will give far more 2nd harmonic. There's also more resistance in the "on"position which should make the extra JFET even less colorful.

Which seems to be that thread's finding: "the fet seems to do f**k all - most of the distortion is in the driving {JFET} stage...".

The EQ schematic is odd, and does not match the PCB around the '741.

> If it's not valve-like, then I'm assuming it can't be too great...

Hmmmph. Seems a rather harsh dismissal.

 

[redmojosteve]

I played in a band many years ago when the VS Musician first came out. One of my bandmates bought one to replace his noisy AC30. It seems strange to think that would happen now. However the HH proved very reliable. HH had the intention of bringing out a line of matching footpedals that could provide various effects which could have looked pretty smart. I don't think many if any were marketed, perhaps just the reverb switch. I thought the overdriven sound was fairly one dimensional and didn't respond at all to string picking dynamics etc. However I thought it sounded much better than the germanium transistor based fuzz boxes around at the time. I still think the latter sound awful, old or new/reissued. Other manufacturers brought out FET based amps, even Marshall had their Mosfet range but they didn't last long. Personally I have always used valve amps for guitar especially Marshall.

 

[LarsfromMars]

They are great amps. Sound like any Buzzcocks, Bauhaus, Bolan record after 73. Some of the Steve Jones dubs on Never mind the bollocks could easily have been done with these amps.

 

[Newmarket]

Quite the thread revival here - 12 Years - But it caught my interest as I used to have (many moons ago 80s into early 90s) a HH VS- Bassamp. The "VS Module" was encapsulated like some precious secret so I never worked out the actual circuit. It was rather effective at low volume. But at higher volume it was more "No Thanks".
VS-Bassamp 100 itself seemed underpowered and so prone to "sag". Some would like that "mush" but not for me. A used early Trace Elliot head was something of a revelation wrt clarity. I can turn my head now and see it although it may have an intermittent fault.
The "old" HH had some good stuff - see VS800 Power Amp - and some 'interesting' financial issues IIRC but I'll stop there

 

[LarsfromMars]

Oh yeah, the VS Musician 2x12 combo amp just came into my hands and i am still excited about how it sounds. Sorry for awakening the dead. The VS 800 power amp was also the choice of EVH for slave amps.

 

[Newmarket]

Oh yeah, the VS Musician 2x12 combo amp just came into my hands and i am still excited about how it sounds. Sorry for awakening the dead. The VS 800 power amp was also the choice of EVH for slave amps.

No need to apologise imo. Yes EVH re VS800. And HH guitar amp is Wilco Johnson's favoured amp.

 

[Newmarket]

Useful website for HH stuff:

MAJ Electronic