I need the Sima W-3050 or W-2002 schematic

[gaetan8888]

Hello

Anybody would have the schematic of the Sima W-3050 or
W-2002 power amp ?

Thank a lot

Bye

Gaetan

[gaetan8888]

Hello

The Sima W-2050 and W-2003 power amp are quite same than the others one, anybody would the schematic for them ?

Thank

Gaetan

[lineup]

seems such schematic is not in internet
i did some google - but nothing found

i am sure some other member would have a schematic
so, if you are lucky here you may have one emailed within 1 week

otherwise, i would say you can try to get in contact with the designer
Victor Sima .. or the people around him

Victor Sima
Proud creator of the entire Linar line as well as
founder and ex-owner of SimAudio
( from this page: http://www.linaraudio.com/NYshow.htm )

The email to Linar Audio is:
linar (at) vif.com

regards

[lumanauw]

If it resembles Linar, maybe this can help you. It's non-global feedback amp, servo, DC coupled. Output transistors and input fets are erased, they could be C5200 and K170?

[gaetan8888]

Hello

Sima amp are 20 years old amp design was before Victor Sima sell his company to Sim Audio, so Linar amp are very different design from Victor, btw a friend of mine do have a Linar 10 and that amp sound superb.

Thank

Gaetan

[pliedtka]

so I to find out I took the board the drew the schematic. I have it on paper somewhere. It uses double diff. pair on input (mpsa 8099, 8599), MPSU07, 57 as predrivers and the MJE15030/21 as drivers and MJ15023/24 out trans. I have problem getting the MPSU07/57 as the smoked , maybe there are newer transistors that could be used as the predriver pair . I thing Victor will not be pissed if send the schematic ( I have to drew it on the Spice) , since all his new amps are no feedback design.
mail me back

[gaetan8888]

Originally posted by pliedtka
so I to find out I took the board the drew the schematic. I have it on paper somewhere. It uses double diff. pair on input (mpsa 8099, 8599), MPSU07, 57 as predrivers and the MJE15030/21 as drivers and MJ15023/24 out trans. I have problem getting the MPSU07/57 as the smoked , maybe there are newer transistors that could be used as the predriver pair . I thing Victor will not be pissed if send the schematic ( I have to drew it on the Spice) , since all his new amps are no feedback design.
mail me back

Hello

I would be very please if you can send it to me by email.

I have sent you a private message.

Thank a lot

Gaetan

[gaetan8888]

Originally posted by pliedtka
MPSU07, 57 as predrivers and the MJE15030/21 as drivers and MJ15023/24 out trans. I have problem getting the MPSU07/57 as the smoked , maybe there are newer transistors that could be used as the predriver pair ...

Hello

MPSU07, 57 as predrivers, I presume it is the transistor for the VAS, those MPSU are slow at 50 mhz, but using much faster modern transistors like 2SC4793, 2SA1837, KSC3503, etc.. may need to change the value of the cdom capacitor, but the BD139 and BD140 would do the job since they are just a bit faster than the MPSU transistors.

Gaetan

[pliedtka]

"like 2SC4793, 2SA1837, KSC3503" I though about the 2SA1837/2SC4793 pair. The BD139/140 is older design might not even be faster than the MPSU's 50-100MHz, what is interesting about the MPSU07/57 is that the Cbo is only 6-12pF (Vcb=10V, Ie=0 f=100khz). Have no idea why Victor used then. Then there is Unisonic (UTC) 2SD669 with low Cbo as well. Also Toshiba 2SA1930/2SC5171 seems OK.
Sorry but I worked on W-kend and didn't do SPICE work for you. My 3050 has 4 transformers instead of two as in original units - maybe two drive low impedance spkr. It's an OK amp, transparent, not soft or romantic, nothing like the later non feedback Celeste 4070(se), 4150 or the latest from Linear, which use MJL21192/93 in the output, I assume. One think I learned from the ordeal: don't bias the output trans more than 10mA per MJ15022/23. Originally they are biased around 5mA (but it did lower the harmonic distortions as my Clio showed)



Paul

[gaetan8888]

Originally Posted by lumanauw

If it resembles Linar, maybe this can help you. It's non-global feedback amp, servo, DC coupled. Output transistors and input fets are erased, they could be C5200 and K170?

Hello

I've open the Linar amp of a friend, we can't see the number on the output transistors, but after asking mr. Sima, it is mosfet output transistors, but I did not give me to number of those mosfet.

Bye

Gaetan