TO-3 SYMASYM

[Atilla]

Hi Rudi,

Can I still order 2 amplifier boards (for a stereo amp)?

I still have some parts I've nothing to do with and this looks like the perfect amp for them 🙂

 

[radio]

A Chinese proverb says: "Give a man a fish not to eat, rather than teaching a man to catch fish"!
cheers

 

[WolleMusic]

Hi radio,

you can find a description on the original page of symaysm: SymAsym5 - Project

Is your question answered with that?

 

[John Luckins]

Hi Rudi,

I've just made Paypal payment of Euros 35.85 for 4 boards.

Nice boards, and thanks for your great work and enthusiasm.

John

 

[Rudi_Ratlos]

I received your payment.
Thank you, John.

There are only 3 transfers missing! I will once more try and contact them!
It would be a pity, if they missed this occasion!



http://www.abload.de/img/statusor5d.png

Best regards - Rudi_Ratlos

 

[Rudi_Ratlos]

Gentlemen,

I still have some very fine, exquisite TO-3 transistors, MJ15022 and MJ15023, at hand.
These transistors will work very well with the TO-3 SYMASYM!

I "LTSpiced" them, did the Fourier Analysis, and the result was impressive indeed!
Have a look at their datasheets, please!

I offer you:

2 sets (2 x 4 pairs) of MJ15022/MJ15023, 1 set needed to build a Stereo TO-3 SYMASYM, along with a spare pair each,
alltogether: 10 x TO-3 transistors, for 25€ per set.



http://www.abload.de/img/joe006rffz.jpg

The transistors are new, have never been used and are 100% authentic OnSemi.

If some of you wants these beauties, write me a PM please.

Best regards - Rudi_Ratlos

 

[Rudi_Ratlos]

The sets of MJ15022/MJ15023 are sold already.
Do not ask me anymore.

Thank you, best regards - Rudi

 

[evette]

Would you like some more? Evette

 

[Rudi_Ratlos]

Dear TO-3 SYMASYM friends,

the group-buy is closed definitely now.

I ordered the PCBs yesterday and am now waiting for the etching company to send me the PCBs' Gerber files for approval.

I will keep you informed.

Best regards - Rudi

P.S. If somebody of you likes to have 100% authentic TO-3 OnSemi transistors MJ15022 / MJ15023: please contact EVETTE directly.
(See post above)

 

[Atilla]

ZTX450 is too noisy for using it in the input instead of MPSA18, right? The noise figure isn't quoted for the ZTX.

 

[Rudi_Ratlos]

I would give the ZTX450 a try, Anton. Why not?

Best regards - Rudi_Ratlos

 

[Atilla]

If I get some good matched pairs, I can give it a shot. But since the datasheet doesn't mention the noise figures, I've no idea if it's good or not. (F.ex. the MPSA18 noise is listed 1.5dB, while the BC550 is 4dB)

 

[evette]

Mr. Rudi you wouldn,t gain anything. Evette

 

[tome]

Hi Rudi
I pay to you yesterday on your bank acc, I hope I'm on your list
regards
tomas

 

[Rudi_Ratlos]

Tomas,

you are of course on my list.

Best regards - Rudi_Ratlos

 

[tome]

thanks

 

[Rudi_Ratlos]

Dear TO-3 SYMASYM friends,

I am happy to tell you that I received a confirmation of the etching company telling me that the PCBs will be etched and shipped on September 30th.

I will then have the PCBs on Wednesday, 4th of October and will meet Sascha, who will do the shipping, on the weekend 8th / 9th of October.

I suppose that most of you will have the PCBs in week 41 (10th to 15th of October).

Best regards - Rudi_Ratlos

 

[AndrewT]

ex. the MPSA18 noise is listed 1.5dB, while the BC550 is 4dB)

at what Ic and what frequency range and what source resistance?

 

[Atilla]

MPSA18: Vce = 5.0V , Ic = 100uA, Rs = 10k, f = 1.0kHz.
BC550: Vce = 5.0V , Ic = 200uA, Rs = 2k, f = 1.0kHz. (Actually listed all over the range - 10Hz to 15.7kHz)

Edit: The datasheets that list that don't seem to all list it under the same conditions, sadly.

 

[AndrewT]

find a datasheet or two or three that have noise graghs for the device.
Plot on those graphs, the two noise figures for the respective devices.
Where these two devices end up, may give you a good clue to how they compare.