Power Supply/ New Build #183 clone

[ToneMerc]

What brand/type of power tubes do you have installed?

TM

[Structo]

I wish all the transformer companies would agree to rate their trannys the same way.

Mine is rated 420v but with the tube load I get 433v rectified on the plates.

[img:364:359]http://lh5.ggpht.com/_MHnI-B0pJ8k/TTSan ... n%20PT.JPG[/img]

[CHIP]

What brand/type of power tubes do you have installed?

TM

Winged C EL34-WC.

[CHIP]

Hey guys,
Would lowering the first power resistor in the string from 3k to 2.4k ,in order to raise my preamp voltages about 10v, cause any differences in tone? or any other problems otherwise?

[talbany]

Chip
.6k won't do much.. I would try to raise it 15-20v try a 1k there should get you closer since your plate voltages are already low..shoot for 300 on PI and 200 on V1

Tony

[CHIP]

Thanks Tony,
My line voltages were low @ 118VAC. I set my variac at 123VAC and it got me within 5 VDC of the proper values. That's with a 10k tacked across the 3K (resulting in 2.4 k).
so it's OK to go as low as 1K if need be?
By the way the amp sounds wonderful, so much more touch sensitivity, bloom and sustain than my "tweaked" D'lite, Very happy with results,
When I get the preamp voltages right should be even better!
Thanks for the layout.

[67plexi]

CHIP, Sweet build you get the gold star award for the first posted non commercial #183 build.
Keep the great work.

[Structo]

Chip I went with a 1K for my first dropper in order to get the preamp and PI voltages up.

Worked well.

I have 284 and 289 on the PI, 203 on V1 and 210 on V2.

But remember that a simple tube change can bring about a 10v change so if you have tubes be sure to audition them.

Try different offerings in V1 for a good clean tone, then shoot for V2 and your overdrive.

[CHIP]

Thanks 67plexi,
Tom,
Tony was right on when he said 1k. with that I'm getting;
v1 191v,199v. v2 200v, 208v. v3 300v, 295v.

v4-7 440v on the plates.

like I've said before The Amp Garage has the best members in the world.
you guys do so much for us amateur builders.
thanks

[Structo]

That's more like it!

I'll bet it sounds great now too.

I find with the Tung Sol 6L6 STR's that I am running that a colder bias seems to work better for me.
These tubes were all right on except one, which was off by a couple ma.
Now they have drifted farther apart but I shoot for 32ma with these.

The bias can and will change the plate voltage a bit so be sure to monitor both while the amp is settling in.

Enjoy!

[Structo]

Chip,
I noticed on your picture you used a filament transformer for the relay supply.
Why did you go that route when Jason's PT has a 6v tap for the supply?

Just curious.

Are you lovin' this amp yet?

[CHIP]

Actually I already had the Radio Shack Tranny, and a Twin PT with no 5v tap and a 6.3v 7A filament supply. When Jason offered his PT, I decided to use his and save the other PT for a future build. . (his has a beefier filament supply for eL34's)
Also since this was my first attempt with relays, I decided not to stray away from the layout.

Amp sounds great, still feeling my way around it.

LOUD.
I plan on hooking up my d'lator like you did, and use it as a master volume.

[CHIP]

a few more pics of the build;

I couldn't be happier with the results. this baby sounded great right from the get go,compared to the D'lite I built, which took me months of tweaking to sound good.
I have no plans to tweak anything. I'm just going to let her settle in. Nothing needs messed with.
the amp is church mouse quiet. No hum at all.

someday when I get some recording gear up and running, I'll post clips.

[grtamp]

great work , what type of the resistor you use in PI stage , katode , OD input? (blue resistor) are KOA SPEER ? MF or CF ?

Thanks

[Chris333]

Are the brown treble and PI caps Xicons? Did you use them specifically for tone, or just because you had them? Can't decide if I like a 6PS or Xicon for a bass cap, but they sound surprisingly different in my 50W...