6V6 line preamp - Page 122

tubo · 8th December 2012, 05:02 PM

Good luck on your work Fellas,

Hopefully I can start with my new build with sshv2 soon. I have been happy with the 6v6 pre for many years without the sshv2. a little bit of hum with AC heaters but tolerable.

DimZ · 9th December 2012, 03:14 PM

tried ss rectifier, IN4007 and a 100Ohm in series before c1, measured 440VDC with no load ...

tested SSHV2 ...

didnt have 8.5Κ dummy load, closest was 7.6K (series 4.7/2.2/0.68) ...

R4 was set to give stable 40mA, but with R11 fully turned I measured 291V across dummy load ...

will try later with 44mA to see if I get 340V across dummy (that is if I done the math correctly

) ...

the whole thing lasted about 5 minutes ... 2540 heatsink run quite hot, 840 heatsink was cold ...

Salas · 9th December 2012, 06:05 PM

Up your load value, its too heavy for your ccs setting.

DimZ · 9th December 2012, 06:16 PM

i have also a 10k/50w resistor trying to find the right comp series/parallel for the dummy load ....

at least sshv2 seems to work ok, when fired up it was set to 140V , trimer adjusted up to 290V ...

Salas · 9th December 2012, 06:21 PM

Try 10K dummy, 55-60mA ccs.

DimZ · 9th December 2012, 06:37 PM

will do that, thanks Nick ...

DimZ · 14th December 2012, 04:01 PM

ss rectification (IN4007) ..

10k dummy - 58mA ccs
a nice 340V B+ ....... had to make a little R11 adjustment after 5 minutes ......

after 15 minutes 840 heatsink slightly warm ...

Salas · 14th December 2012, 04:12 PM

Looks like doing OK.

DimZ · 14th December 2012, 04:18 PM

yeap,
couple of little things to solder , some cable management and should be ready to go ...

mgreene · 14th December 2012, 06:13 PM

DimZ, I am following your recent posts. Are you planning to do a listening test: IN4007 vs 274B? I would love to hear about that.

I have all the parts for my build but am on the fence about the rectifier - only because I was making an order from Antek and got a toroid for the Salas project too - but w/o a 5V winding.

Note that I am currently using my version of the "International Loesch" preamp which uses a soild state bridge and still sounds fabulous.

Mike

14th December 2012, 06:13 PM	#1220
mgreene diyAudio Member Join Date: Jun 2002 Location: Aiken, South Carolina USA	SS vs Tube rectifier DimZ, I am following your recent posts. Are you planning to do a listening test: IN4007 vs 274B? I would love to hear about that. I have all the parts for my build but am on the fence about the rectifier - only because I was making an order from Antek and got a toroid for the Salas project too - but w/o a 5V winding. Note that I am currently using my version of the "International Loesch" preamp which uses a soild state bridge and still sounds fabulous. Mike

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8th December 2012, 05:02 PM	#1211
tubo diyAudio Member Join Date: Apr 2007	Good luck on your work Fellas, Hopefully I can start with my new build with sshv2 soon. I have been happy with the 6v6 pre for many years without the sshv2. a little bit of hum with AC heaters but tolerable.

9th December 2012, 03:14 PM	#1212
DimZ diyAudio Member Join Date: Nov 2007 Location: athens	tried ss rectifier, IN4007 and a 100Ohm in series before c1, measured 440VDC with no load ... tested SSHV2 ... didnt have 8.5Κ dummy load, closest was 7.6K (series 4.7/2.2/0.68) ... R4 was set to give stable 40mA, but with R11 fully turned I measured 291V across dummy load ... will try later with 44mA to see if I get 340V across dummy (that is if I done the math correctly ) ... the whole thing lasted about 5 minutes ... 2540 heatsink run quite hot, 840 heatsink was cold ...

9th December 2012, 06:05 PM	#1213
Salas diyAudio Chief Moderator Join Date: Oct 2002 Location: Athens-Greece	Up your load value, its too heavy for your ccs setting.

9th December 2012, 06:16 PM	#1214
DimZ diyAudio Member Join Date: Nov 2007 Location: athens	i have also a 10k/50w resistor trying to find the right comp series/parallel for the dummy load .... at least sshv2 seems to work ok, when fired up it was set to 140V , trimer adjusted up to 290V ...

9th December 2012, 06:21 PM	#1215
Salas diyAudio Chief Moderator Join Date: Oct 2002 Location: Athens-Greece	Try 10K dummy, 55-60mA ccs.

9th December 2012, 06:37 PM	#1216
DimZ diyAudio Member Join Date: Nov 2007 Location: athens	will do that, thanks Nick ...

14th December 2012, 04:12 PM	#1218
Salas diyAudio Chief Moderator Join Date: Oct 2002 Location: Athens-Greece	Looks like doing OK.

14th December 2012, 04:18 PM	#1219
DimZ diyAudio Member Join Date: Nov 2007 Location: athens	yeap, couple of little things to solder , some cable management and should be ready to go ...