Pcb 300 W - Page 3

fjromero · 13th November 2006, 07:04 PM

to see if this scheme is the correct one, warm greetings.

K-amps · 13th November 2006, 07:17 PM

If you are open to changing the OP devices, why would you not use the much better MJ21195/96? Stability?

Jan Dupont · 13th November 2006, 07:21 PM

Three pairs of output devices are still not enough to safely handle 280/350W at a 45 degree phase angle

K-amps · 13th November 2006, 07:28 PM

Took another look... its an old design (maybe later) with 20 year old parts... TL071???

Lowering the rails to +/-70 should do it... or add another pair.

I have used a similar design with +/-68vdc. 4 pairs of 15003/4 and they ran four jbl 2225's all day. i.e. 2 ohm loads.

edl · 13th November 2006, 07:30 PM

Quote:

Originally posted by ACD
Three pairs of output devices are still not enough to safely handle 280/350W at a 45 degree phase angle

Hi,

PL400-II (almost the same schematic) used 3 pairs of MJ15024 at 80V rails!

Regards,

Jan Dupont · 13th November 2006, 07:38 PM

Quote:

PL400-II (almost the same schematic) used 3 pairs of MJ15024 at 80V rails!

The Phase Linear 400-II are notorius known for their weak output circuit.......

I have personally repaired/replaced output devices on app. 20 different PL400's over the year, even though the PL400 never was very popular in little Denmark and I have never worked at an official PL workshop

K-amps · 13th November 2006, 07:53 PM

Quote:

Originally posted by ACD

The Phase Linear 400-II are notorius known for their weak output circuit.......

I have personally repaired/replaced output devices on app. 20 different PL400's over the year, even though the PL400 never was very popular in little Denmark and I have never worked at an official PL workshop

Not having touched one before, was the heatsinking adequate? Didnt Bob carver use a 125v mains cap with 130v supply in one design?

Jan Dupont · 13th November 2006, 08:00 PM

Heatsinking was ok I think ...
However I never actually measure the temperature

Bob Carver did made some strange choices in his desig, however so did many others....
Remember the Onkyo M504 ?? Output caps did go

all the time, even though it was a good amp

Just because it was a commercial amp, doesn't make the circuit right.... That's why we make DIY

fjromero · 13th November 2006, 08:32 PM

That it seems to you this other scheme.
greetings

K-amps · 14th November 2006, 12:21 AM

Personally I like this one better.... non-reactive 2 ohm load is possible with this depending on supply droop. Though I still prefer the MJ21193/4/5/6 because of better gain.. either that or you get more robust drivers.... Though I have always liked the 669/649's...

13th November 2006, 07:21 PM	#23
Jan Dupont diyAudio Member Join Date: Apr 2003 Location: Copenhagen, Denmark	Three pairs of output devices are still not enough to safely handle 280/350W at a 45 degree phase angle __________________ Free Schematic and Service Manual downloads www.audio-circuit.dk, Company: www.dupont-audio.com, Joint venture: www.DupontMantra.com

13th November 2006, 08:00 PM	#28
Jan Dupont diyAudio Member Join Date: Apr 2003 Location: Copenhagen, Denmark	Heatsinking was ok I think ... However I never actually measure the temperature Bob Carver did made some strange choices in his desig, however so did many others.... Remember the Onkyo M504 ?? Output caps did go all the time, even though it was a good amp Just because it was a commercial amp, doesn't make the circuit right.... That's why we make DIY __________________ Free Schematic and Service Manual downloads www.audio-circuit.dk, Company: www.dupont-audio.com, Joint venture: www.DupontMantra.com

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13th November 2006, 07:04 PM	#21
fjromero diyAudio Member Join Date: Oct 2006	to see if this scheme is the correct one, warm greetings.

13th November 2006, 07:17 PM	#22
K-amps diyAudio Member Join Date: Nov 2003 Location: Indiana	If you are open to changing the OP devices, why would you not use the much better MJ21195/96? Stability?

13th November 2006, 07:28 PM	#24
K-amps diyAudio Member Join Date: Nov 2003 Location: Indiana	Took another look... its an old design (maybe later) with 20 year old parts... TL071??? Lowering the rails to +/-70 should do it... or add another pair. I have used a similar design with +/-68vdc. 4 pairs of 15003/4 and they ran four jbl 2225's all day. i.e. 2 ohm loads.

13th November 2006, 08:32 PM	#29
fjromero diyAudio Member Join Date: Oct 2006	That it seems to you this other scheme. greetings

14th November 2006, 12:21 AM	#30
K-amps diyAudio Member Join Date: Nov 2003 Location: Indiana	Personally I like this one better.... non-reactive 2 ohm load is possible with this depending on supply droop. Though I still prefer the MJ21193/4/5/6 because of better gain.. either that or you get more robust drivers.... Though I have always liked the 669/649's...