Modify your Woo 6. . Sophia and EML 274B . Images pages 32, 33, 34 of int. and ext. and discussion of the SE . . .
Apr 1, 2008 at 4:45 AM Post #16 of 893
Yes, also you do not want too much capacitance for the 1st cap or you will stress the rectifier as a cap looks like a short to ground at first until it is charged. One nice thing about the indirectly heated 34 and others that are indirectly heated is that they bring up the voltage slowly where a directly heated rectifier comes on fairly fast, has to have a small first cap and in my opinion can be a little harder on tubes because they get hit with the full B+ before they have come on totally.


Quote:

Originally Posted by takezo /img/forum/go_quote.gif
i figured starting the parallel run from the rectifier would be better
than after the first power filter cap, but i see what you mean...so,
you'd suggest i run two resistors off the first power filter cap after
the rectifier? thanks



 
Apr 1, 2008 at 4:58 AM Post #17 of 893
thanks for the insight, john. i completely neglected to consider the
strain on the rectifier from an increase in the first cap...much thanks!
 
Apr 1, 2008 at 5:07 AM Post #18 of 893
Carry Audio used to make a SLA50 stereo amp. I bought one when they first came out in 1990. I upgraded it with their newest output transformers as they came along but anyway what they did was have two rectifiers in parallel but even with them in parallel they still had a 1000uf cap that the rectifiers first had to fill! Well it really stressed rectifiers and I ruined some very good ones because they would arc, which degrades them very fast. So I put in a L90 or was it a CL90, anyway it is a thermistor that with the first current flow heats up and slows the current flow because of the resistance it creates but as the cap is charged and the current slows the thermistor cools and the resistance drops to zero. It saves the rectifiers and slows the B+ some to the other tubes. If I don't need to I prefer not to use the CL90 though.
 
Apr 1, 2008 at 7:42 PM Post #19 of 893
More time needed for the caps to form. The bass is very fast, solid and tight but I like it to be a little more organic in nature. It is like a solid state amp right now in the delivery, a good one but I like what is to me, a slightly different presentation. Also my coupling caps need serious upgrading, very serious.

Detail and separation is extremely good with dynamics fast and sure.
 
Apr 2, 2008 at 1:49 AM Post #20 of 893
Well I doubled the coupling caps by adding another stock .1uf to the .1 that was there, which gives me a combo nearer what I like, which is a normal .22uf. I like the mids better. The new caps are forming well in the power supply and the dual supply to the output tubes does help. I can turn the amp off and it continues to play for about 15 seconds. I would say that is enough reserve while on for some good bass control and good clean DC. I like the sound I am hearing in all areas.

Next will be to change out the coupling caps to some Mundorf gold and silver .22uf. They are excellent in all areas.
 
Apr 2, 2008 at 2:08 AM Post #21 of 893
Are there any Bay Area meets coming up? I live in Santa Cruz and work in Mountain View and I ordered a Woo6 with just the $30 blackgate upgrade last week, should be done in 3 weeks. I would LOVE to hear how much the things you have done improve the sound over a stock unit.
 
Apr 2, 2008 at 2:12 AM Post #22 of 893
I almost took a job in Santa Cruz but wasn't crazy about the hospital. I don't know of any meets but then I am not up to speed on them. I love what I am hearing right now. normally I do everything at once or in just a couple of steps so it is nice to hear these gradual changes, for a change.

I don't want to take the headphones off. I hate it when this happens because I have things to do. Ah music. Interesting how the same music can be so inviting when reproduced so well. Well, here I am. . Well. . . well. got to go. . . well. ... . . . . . . . . . well. . . wel .. . . we. . . . . .w . . . . . .
 
Apr 2, 2008 at 2:45 AM Post #23 of 893
good to hear you're enjoying the modified unit...i've ordered a power filter cap
and a couple of the mills resistors via sonicraft. they told me i should get it in
2-3 days...
 
Apr 2, 2008 at 5:56 AM Post #25 of 893
Quote:

Originally Posted by takezo /img/forum/go_quote.gif
good to hear you're enjoying the modified unit...i've ordered a power filter cap
and a couple of the mills resistors via sonicraft. they told me i should get it in
2-3 days...



What coupling caps do you have in yours? The V-caps or something else?
 
Apr 2, 2008 at 2:49 PM Post #26 of 893
i've used dynamicap, auricap, jensen copper, mundorf silver in oil and v-cap so
far in my wa6...for my taste, i'd have to say the mundorf and jensen are my
favorite by a smidgen over the v-cap...the paper in oil caps have a velvety
smooth sonic characteristic that's hard to describe with words...here's a poor
attempt at another analogy: the v-cap present sounds that are ultra clean and
hard impenetrable surface, like a marble table, with high resolution...
the paper in oil caps present sounds that are silky smooth with texture that's
more emphasized than the v-cap, though not as high in resolution, if that makes
sense...and for that tubey sound, the paper in oil caps seem to have better
and longer decay than the teflon, especially with vocals and mid bass regions,
which some like and some don't...

after the power supply mod, i'm going to roll the caps all over again, just for fun!

btw, i've been recabling my senn 650 recently and have to admit i've been getting
some amazing improvement...i think i prefer it over the 701 now...
 
Apr 2, 2008 at 3:50 PM Post #27 of 893
Quote:

Originally Posted by takezo /img/forum/go_quote.gif
i've used dynamicap, auricap, jensen copper, mundorf silver in oil and v-cap so
far in my wa6...for my taste, i'd have to say the mundorf and jensen are my
favorite by a smidgen over the v-cap...the paper in oil caps have a velvety
smooth sonic characteristic that's hard to describe with words...here's a poor
attempt at another analogy: the v-cap present sounds that are ultra clean and
hard impenetrable surface, like a marble table, with high resolution...
the paper in oil caps present sounds that are silky smooth with texture that's
more emphasized than the v-cap, though not as high in resolution, if that makes
sense...and for that tubey sound, the paper in oil caps seem to have better
and longer decay than the teflon, especially with vocals and mid bass regions,
which some like and some don't...

after the power supply mod, i'm going to roll the caps all over again, just for fun!

btw, i've been recabling my senn 650 recently and have to admit i've been getting
some amazing improvement...i think i prefer it over the 701 now...



I have long liked the Mundorf silver supreme. I understand the gold and silver oil have a slightly higher resolution. I use the Mondorf in my speaker crossover and have used them in amps etc.

I think the Audio Note copper and oil are a little better than the Jensen. I am debating between the silver and gold Mundorf or the silver.
 
Apr 2, 2008 at 4:03 PM Post #28 of 893
yes, i really like the mundorf caps and i got them cheaper than the jensen copper thru soniccraft...
soniccraft is having a special on mundorfs right now and seem to be 10 -20%
cheaper on mundorf caps than partsconnexion at the moment on film caps...they
dispatch rather quickly too...they don't carry the silver/gold/oil caps though...
 
Apr 3, 2008 at 12:51 AM Post #29 of 893
Quote:

Originally Posted by takezo /img/forum/go_quote.gif
yes, i really like the mundorf caps and i got them cheaper than the jensen copper thru soniccraft...
soniccraft is having a special on mundorfs right now and seem to be 10 -20%
cheaper on mundorf caps than partsconnexion at the moment on film caps...they
dispatch rather quickly too...they don't carry the silver/gold/oil caps though...



It is the silver and gold oil cap I would really like to try. I have used the silver Mundorf and they are very good and perform above their price.

The power supply modification is doing very well and really changes the complexity of music that the amp can handle, like nothing is too complex or difficult. The bass is really well controlled and solid.

Oh, and the openness and transparency of well recorded music is . . . well you'll find out.
 
Apr 5, 2008 at 12:16 AM Post #30 of 893
took me a couple of hours to desolder and redo the power supply but here's
my messy result:

wa6mod14.jpg

wa6mod05.jpg


i'm listening to the wa6 as i type and i can't put my finger on it, but it seems
different to me...i think i have to let it burn-in and settle a bit before i try to
figure out what's different and how...my 650 sounds different...
 

Users who are viewing this thread

Back
Top