Studio Reference Amplifier - Page 34

apexaudio · 28th June 2011, 07:07 PM

Quote:

Originally Posted by dentarthur

Anyone else done this too?
I run SR200 on +/- 70V and found that 5 transistors get pretty hot. It all works just fine, however, I made some cooling on the MJE transistors and the 2 BC550's that connect to the + via the 100ohm resistors (see picture).

Isn't it strange that the 2 BC550's on the '-' side do not get as hot as the ones on the + side?

It's strange that the 2 BC550 get hot. MJEs must be hot and BCs must be cold in cascode VAS...

drowranger · 29th June 2011, 04:33 AM

why is resistor r9 and r10 is before the r11.how can you get the ideal 4ma when your voltage is only 15volts?

Luke · 29th June 2011, 05:18 AM

anyone made a pcb for the higher power reg as in post 14?

drowranger · 29th June 2011, 02:52 PM

anyone?can you please help me on r9 and r10.is it before r11 or after?check me if im wrong r9, r10,d2, and c5 are used to regulate the supply of ic1. im making new foil pattern for this one. thank you for your time.

apexaudio · 1st July 2011, 01:23 PM

Quote:

Originally Posted by mathez

thanks to Apex&Alex for this SR200

Nice work, be welcome,
Regards

apexaudio · 1st July 2011, 01:25 PM

Quote:

Originally Posted by dentarthur

I have built one SR200 and have it running on +/- 70V.
I can set bias for it to be at 100mA (10Ohm resistors do not go up in flames).
However, the MJE 340/350 all get very hot. During short up-times I did some measuring and it seems that each of these MJE's has approx 67V between E-C and runs some 10mA. Should these T's get warm with these numbers? Should I heatsink them (I see heatsinks on them in some builds.
Or does this mean that there is an error in my build?

Yes, MJE's need cooling, there is no error,
Regards

drowranger · 2nd July 2011, 05:57 AM

Quote:

Originally Posted by apexaudio

APEX SR100 Studio Ref Amp

Hope this may help(based on the original schematics of SR50).

ENJOY!!!

drowranger · 2nd July 2011, 07:58 AM

correct parts placement guide.(previous is in mirror image).sorry.

drowranger · 2nd July 2011, 02:18 PM

Quote:

Originally Posted by drowranger

correct parts placement guide.(previous is in mirror image).sorry.

yassud · 10th July 2011, 11:38 AM

Quote:

Originally Posted by apexaudio

You can use Coolets pcb design for SR50 and add another pair of outputs,
Regards

Sir Apex, can you give examples of schemes SR100 (VAS cascode)? Thank You

29th June 2011, 05:18 AM	#333
Luke diyAudio Member Join Date: Sep 2001 Location: Wellington NZ	anyone made a pcb for the higher power reg as in post 14? __________________ If you give a man a fish he will eat for a day. But if you teach a man to fish he will buy an ugly hat. And if you talk about fish to a starving man then you are a consultant. Dilbert

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Crown Studio Reference I: beefing up the power supply	elac310	Power Supplies	4	28th April 2010 12:50 AM
Reference Amp for studio	exhausted mule	Solid State	0	5th June 2006 05:39 AM
studio amplifier project?	rotation	Chip Amps	2	2nd February 2006 04:33 AM
Any website reference for diy Audio Research REFERENCE amp and Manley Studio amp	bmpa	Tubes / Valves	4	19th April 2004 05:11 AM
Any information , website reference for diy Hi-End computer studio sound card?	bmpa	Digital Source	5	16th April 2004 04:57 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

29th June 2011, 04:33 AM	#332
drowranger diyAudio Member Join Date: Aug 2009	why is resistor r9 and r10 is before the r11.how can you get the ideal 4ma when your voltage is only 15volts?

29th June 2011, 02:52 PM	#334
drowranger diyAudio Member Join Date: Aug 2009	anyone?can you please help me on r9 and r10.is it before r11 or after?check me if im wrong r9, r10,d2, and c5 are used to regulate the supply of ic1. im making new foil pattern for this one. thank you for your time.