Has anyone used the TO-3P package MJ21193/4 for the amp? Looks like mouser has them or are we better off with NJW0302G/NJW0281G or even NJW3281G/NJW1302G?
Will the large Sankens fit this board? I saw that the would be troublesome on the TO-3 board but has anyone tried them for the TO-3P board? 36.4mm VS 20mm width...It does not appear that there is at least 8mm on either side according to the drawing I saw in this thread.
Lastly...can someone explain what drives the need for reducing the feedback cap? Is is the speed or the output capacitance?
Will the large Sankens fit this board? I saw that the would be troublesome on the TO-3 board but has anyone tried them for the TO-3P board? 36.4mm VS 20mm width...It does not appear that there is at least 8mm on either side according to the drawing I saw in this thread.
Lastly...can someone explain what drives the need for reducing the feedback cap? Is is the speed or the output capacitance?
Attachments
Carl, the big SANKENs (like 2SC2922 and 2SA1216) do not fit on the PCB.
I have built a SYMASYM with MJ21193 / MJ21194 TO3-transistors myself.
So: MJL21193 / MJL21194 (TO264 - case) will do it.
I will try and describe the sound differences between the different types of the transistors in the EMail that I will send you this afternoon.
Best regards - Rudi
P.S. Carl: please have a look at this article: http://web.telecom.cz/macura/symasym.html
I have built a SYMASYM with MJ21193 / MJ21194 TO3-transistors myself.
So: MJL21193 / MJL21194 (TO264 - case) will do it.
I will try and describe the sound differences between the different types of the transistors in the EMail that I will send you this afternoon.
Best regards - Rudi
P.S. Carl: please have a look at this article: http://web.telecom.cz/macura/symasym.html
Last edited:
Hello everyone ,,a very quick run down on the type of output transistors to use for your amplifer. I,ve used every device listed by Mr.Rudi. I would not recomend the 2sk5200 transistors at all they sound terrible to me and I,m too lazy to play with them . The best of course are the to-3 type of transistors. However If you really want the to-3 package you are better off with the NJL0281/0302 series. These devices well put you in heaven.
This is of course my taste only. so Gentlemen when you recieve your pcb please feel free to play with your new amp and don,t be afraid to try different transistors it,s really hard to get this amp to sound bad. And of course use the biggest tranformer you can afford, this amp will love you for it. Thanks every body for hearing me rant on. Regards Evette
This is of course my taste only. so Gentlemen when you recieve your pcb please feel free to play with your new amp and don,t be afraid to try different transistors it,s really hard to get this amp to sound bad. And of course use the biggest tranformer you can afford, this amp will love you for it. Thanks every body for hearing me rant on. Regards Evette
Gentlemen, let me give you some further information regarding this group-buy.
1) I received the confirmation for my PCB-order today.
Dear Rudi,
Your order is confirmed Sep 7, 2012 15:03 and scheduled to ship on Sep 17, 2012.
We will send you delivery details as shipped. Please let us know if had any questions, thank you.
2) I already received the 0R22 emitter resistors today.
The resistors are MPC74 type of resistors, non-magnetic.
I will enclose 4 pcs. for every PCB that you ordered in your letters.
So please do not include these resistors into your BoM.
When you solder them, be sure to leave some space below them, so the air can flow unhindered.
3) I checked the size of the ALU-L profile this morning.
In contrast to what I wrote you in my EMail: use 40 x 40 x 4mm ALU-L profiles with a length of 141mm. All type of transistors will fit on it.
4) I went through Carl's BoM. It looks good.
But I am unhappy that MOUSER does currently not offer the Vishay MKT1822 capacitor (used as C1 input capacitor).
If you need an input-capacitor on your AMP's PCB (the input capacitor blocks DC; maybe your music source already blocks DC on the output)
and you would like to have the MKT1822 (which is my favourite):
Description of the MKT1822 as found in "Humble Homemade Hifi":
Vishay MKT1822 MKT 63VDC – 1% tolerance
Technical specifications: Metallized polyester film with vacuum deposited aluminium. Main applications: blocking, bypassing, filtering, timing, coupling and decoupling circuits, interference suppression in low voltage applications.
Sound: Well balanced, overall coherent sounding capacitor. It doesn't have as much depth as the more “high-end” type capacitors and micro-detailing is limited but somehow it did stay in the back of my head as “nice”. You can boost the overall presentation a lot by adding 0,01uF's worth of MKP1837 parallel. So if you are looking for a cost effective and very compact alternative to MKP capacitors like the Solen Fast Cap, look no further!
... I can order a pair of MKT1822 / MKP1837 from the German distributor BUERKLIN for you and put them into your letters.
The price of a pair is about 5€.
(Please consider shipping cost from BUERKLIN resp. RSONLINE.)
Best regards - Rudi
1) I received the confirmation for my PCB-order today.
Dear Rudi,
Your order is confirmed Sep 7, 2012 15:03 and scheduled to ship on Sep 17, 2012.
We will send you delivery details as shipped. Please let us know if had any questions, thank you.
2) I already received the 0R22 emitter resistors today.
The resistors are MPC74 type of resistors, non-magnetic.
I will enclose 4 pcs. for every PCB that you ordered in your letters.
So please do not include these resistors into your BoM.
When you solder them, be sure to leave some space below them, so the air can flow unhindered.
3) I checked the size of the ALU-L profile this morning.
In contrast to what I wrote you in my EMail: use 40 x 40 x 4mm ALU-L profiles with a length of 141mm. All type of transistors will fit on it.
4) I went through Carl's BoM. It looks good.
But I am unhappy that MOUSER does currently not offer the Vishay MKT1822 capacitor (used as C1 input capacitor).
If you need an input-capacitor on your AMP's PCB (the input capacitor blocks DC; maybe your music source already blocks DC on the output)
and you would like to have the MKT1822 (which is my favourite):
Description of the MKT1822 as found in "Humble Homemade Hifi":
Vishay MKT1822 MKT 63VDC – 1% tolerance
Technical specifications: Metallized polyester film with vacuum deposited aluminium. Main applications: blocking, bypassing, filtering, timing, coupling and decoupling circuits, interference suppression in low voltage applications.
Sound: Well balanced, overall coherent sounding capacitor. It doesn't have as much depth as the more “high-end” type capacitors and micro-detailing is limited but somehow it did stay in the back of my head as “nice”. You can boost the overall presentation a lot by adding 0,01uF's worth of MKP1837 parallel. So if you are looking for a cost effective and very compact alternative to MKP capacitors like the Solen Fast Cap, look no further!
... I can order a pair of MKT1822 / MKP1837 from the German distributor BUERKLIN for you and put them into your letters.
The price of a pair is about 5€.
(Please consider shipping cost from BUERKLIN resp. RSONLINE.)
Best regards - Rudi
