Sluckey AB763 DELUXE LITE-MV

[adamG]

Hi Guys,

Can you advice me how to implement Master Volume into this circuit?
Also, I'd like to buid it with 2x 6L6, as Showman is.
Thank you in advance.

Regards,

Adam

[sluckey]

The easiest thing to do would be replace R13 and R14 with a 500KA pot. If you want a post PI master just search for LarMar PPIMV. Lot's of discussion and pics right here. Plenty more on the net.

Layout would be the same for 2X6L6. Change a couple dropping resistors in the power supply, tweak the bias circuit to provide ≈-50v, and use bigger iron. Compare the Showman schematic to the lite schematic.

[adamG]

Thank you very much!
When the amp is ready, I'll publish it here;)

Regards,

Adam

[Willabe]

Umm, that's Sl U ckey.

[adamG]

Hi again,

Showman is done
I am very much delighted with results of this amp.
I prefer Dumblish circuits ,but this baby is really amazingly sounding. Its sonic character is warm, soft and very smooth.
I set the power stage HT approx. 450V as 80W Showman is. So, I wanted to tweak its power to 45-50W.   
Both knobs Vol. and MV cooperate very well ,co I can gain preamp into smooth overdrive as I like.

Beside of above, I have a question to you.
Feetback loop doesn't work as it suppose to. When digital reverb is plugged into, annoying harsh interferences appear, especially when I plug guitar into Hi input.
I susspect that maybe the preamp gain is too high?!
What do you think about it?

Regards,

Adam

[adamG]

A couple more photos.

Adam

[tubenit]

Very nice build!  Regarding the FX tone ................... maybe consider building an external FX loop similar to a D'lator?

http://ampgarage.com/forum/viewtopic.php?t=18896&highlight=loop

With respect, Tubenit

[adamG]

Thank you T., but I need to investigate the reason of this passive one onboard.
The amp was to be a budget one and I do not want to rip it by adding another tube
Any other suggestions?

Regards,

Adam

[sluckey]

Very nice looking build. Seems to be more sophisticated than my simple Deluxe Lite.

You say "Feetback loop doesn't work as it suppose to." Are you referring to the negative feedback loop? Or are you referring to your send/return fx loop? If fx loop, please describe how it is connected. An as built schematic would be very helpful.

[adamG]

Thank you S. very much.
Amp is for my friend,jazz player, so he needs the effects loop.
The issue is -return-send- jacks.
This evening I'll scan your schematic with loop put on.
It seems very strange that loop generate slightly overdrive sound, when reverb is plugged into.

Regards,

Adam

[sluckey]

Are you using a reverb unit that's designed to be plugged into the input jack?

[adamG]

Yes, I use digital pedal reverb plugged into jacks.
Here's you "modified" schematic of Deluxe.
I double checked those conns. and they seem to be ok.
It's not the first time ,when I provide the effects loop.
Nevertheless ,I could make some stupid error;)
Voltages:
V3-3 - 452 ,4-448V , (same volt.V4) - (power stage),
V2-3,8 - 95V ,2 and 7-62V approx., 1-250V , 6-236V (driver),
V1-1 - 280V , 6-285V (input tube)

Thank you and regards,

Adam

[sluckey]

That's how I would do a passive loop, except that I would connect the switch lugs of both jacks together so preamp signal can pass to power amp when nothing is plugged into the loop.

Try this... Use a patch cable to connect send and return jacks together. If the amp sounds normal there is nothing wrong with the amp or your wiring of the jacks. In this case the instrument level reverb unit you are using is just not compatible with this passive loop. The amplified guitar signal at the input to the send jack should approximately 1V which is probably much too high for your reverb unit.

I've built several amps with passive send/return jacks just as you have done. But I never used them as a fx loop. I simply used them as preamp out and power amp in jacks for the purpose of patching this preamp to an external power amp or patching an external preamp into this power amp.

[adamG]

That's professional assistance.
Thank you S.,very much!

I hope I'll build this great amp again, soon.
I recomend it with above voltages.
Very versatile, simple and good sounding machine!

Best regards,

Adam