Pearl Two

[Zen Mod]

I'm not playin' guitar ( abandoned learning as teen , having too much other things on mind) , but I repaired numerous guitar amps , re-done more than few guitars - wiring , screening , custom switching arrangements etc.

Magma is French ( not that we didn't had wakoo bands )

[bnorrish]

The clip I saw did not sound like French - Kobaian? Typical dumb American view of the world I have.

From Wikipedia:
In a 1977 interview with Vander and long-time Magma vocalist Klaus Blasquiz, Blasquiz said that Kobaïan is a "phonetic language made by elements of the Slavonic and Germanic languages to be able to express some things musically. The language has of course a content, but not word by word."

[Wellerman]

Originally Posted by Salas

As for the spot on importance question, look at this Toshiba chart. Its the transconductance VS drain current. As you see 5 to 5.6 is practically the same just above the 30 millisiemens mark. So your input stage gain is very close to the original (23mA/4JFETS=5.75mA each on average VS 5mA in original). The larger resistors promote better sharing also. Wayne knew that there is an optimal region at about 5-6mA for the type no matter if adding a bit of nVsqrtHz from the net Rs resistance (Value/4). Its a thermal trade off for each one's dissipation at IDSS and noise most probably. 8.5V or 9.4V VDS at about 0.1V VGS look linear alike. Gate leakage current should be very close too. In a nutshell you should be sorted as you are.

Just to improve my understanding of matters: my quads have around 27-27,5mA. Voltage drop across R21-R24 is within 1mV in a quad (67-68mV, 68-69mV). I have lowered R10 (4k7) to get Vc 6.1 Vb 5.9 and Ve 5.3V around Q3. So there is 5.3V on the drains of Q6-9. Is that in a range where the 2SK170 works less well? What could be the effects on the sound quality? Audible? If the higher mA means higher gain I would actually welcome that (unless of course it degrades sound quality)

[Salas]

The curves are steeper there. Bit less linear.

P.S. There was some technical and subjective mix test maybe from a German site that was recommending them at >6.5V but I can't find it now. You better listen on your own with higher source resistors and decide.

[Zen Mod]

Originally Posted by bnorrish

The clip I saw did not sound like French - Kobaian? Typical dumb American view of the world I have.

From Wikipedia:
In a 1977 interview with Vander and long-time Magma vocalist Klaus Blasquiz, Blasquiz said that Kobaïan is a "phonetic language made by elements of the Slavonic and Germanic languages to be able to express some things musically. The language has of course a content, but not word by word."

they're , in fact , World's Citizens , in best meaning of the word

at least to my ( limited ) knowledge , they are having exactly right amount of French wakoosness , and rest is ...... simply put - I adore their music

[bnorrish]

Originally Posted by Salas

The curves are steeper there. Bit less linear.

In general, does operating in the less linear range of a device mean more distortion?

[bnorrish]

I will need to add some Magma to my collection. I have a fair number of Brit Prog rock (Yes, ELP, King Crimson, Genesis) - quick search and Magma vinyl fetches a premium.

[Joachim Gerhard]

lab page

[Salas]

Yes, that was the German link. Thanks Joachim.

[richluvsound]

Rosewood Pearl with hand built case .... still need to put the Power switch in ...