6V6 line preamp

[RCruz]

 

[DimZ]

changed sides so sshv2 cabling will be easier ...

finished the 2nd ps for 6v6 fil, and did a first test of the main ps using a 274b rectifier, measures just like psudII ...

next is to test the sshvII ....

almost there ....

An externally hosted image should be here but it was not working when we last tested it.

 

[merlin el mago]

DimZ can't see the pic.

 

[DimZ]

now ?
AVClub

 

[merlin el mago]

It needs to be registered!

 

[DimZ]

hope i got it this time ...

 

[merlin el mago]

Nice to see your work in progress.

 

[buzzforb]

Your gonna really enjoy this pre gentlemen. I like it with the BA3 and F6

 

[DimZ]

no BA3 or F6 here buzzforb ..

only a f5 and a zenv4, I think that you didnt like the 6v6/f5 comb ....

 

[buzzforb]

I haven't tried it with F5T, but did not like it with F5. Just an opinion, though. I would guess that you like it with ZV4, but time will tell.

 

[tubo]

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]

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]

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

 

[DimZ]

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]

Try 10K dummy, 55-60mA ccs.

 

[DimZ]

will do that, thanks Nick ...

 

[DimZ]

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]

Looks like doing OK.

 

[DimZ]

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

 

[mgreene]

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