Latest project - Transcendent GG Pre

[BlueMDPicker]

I've been wanting to build this for awhile. Since I setup my old Maggies again, driven by a Counterpoint SA-100, I needed a bit more gain with that combo than my SE OTL/Shanling rig requires. So, I finally ordered it last week. It arrived at 5:00 p.m. yesterday and was built by midnight (with MANY interruptions) - actual build time was really about 4 hours.

I modded the power indicator LED with a stainless steel bezel mount and low (300) mcd, 5V blue LED to match the Shanling's lovely blue glow. Have the dropping resistors ordered to do the same to the two SE OTLs and Balanced Power Supply LEDs. Replaced the stock caps with Kimbers. Running 3 Ei 12AU7s for the break-in, then I'll start rolling some goodies through it. The circuit can be easily modded (change out four resistors) to run 12AT7s for 30 db gain if desired.

Sounds great this morning, dead quiet and smooth gain.

[BlueMDPicker]

Guts

[audiobliss]

Sweet! That looks real nice! And, more importantly, it seems it sounds nice, too.

[steveinaz]

Very cool! Great idea on the LED mod. I wish my DAC's LEDS weren't so bright.

[Tour2ma]

Pre's with their tops popped make me nervous....

Nice...

[RuSsMaN]

Tour, they should, dumbass.

Mike, let me know if you need any exotic 12AT7's - I've got TONS of them.

Cheers,
Ruiss

[BlueMDPicker]

Originally posted by steveinaz
Very cool! Great idea on the LED mod. I wish my DAC's LEDS weren't so bright.
Thanks!

Here's a handy, web-based calc that makes it a no-brainer to work with LEDs. Find the operating voltage supplied to your DACs LED (before the dropping resistor), get another LED more to your tastes with a new resistor, and no more etched retinas from across the room. ;)

LED Series Resistor Calculator (http://ourworld.compuserve.com/homepages/Bill_Bowden/led.htm)

[BlueMDPicker]

Originally posted by RuSsMaN
Mike, let me know if you need any exotic 12AT7's - I've got TONS of them.

Will do Russ, thanks! For the time being, the 12 db gain from the 12AU7s is working well with the Counterpoint. If I get to playing around with some home brew SET/SEP stuff, I may crank her up a notch with the AT7s.

[DAGLJAM6]

That will replace the CJ pre sometime this summer, I feel the need to step it up a notch.... and for the price ,kit or built, you can't go wrong.

[Vr3MxStyler2k3]

Does that thing have 3 power supplies???:confused:

Looks awesome! Wish I could hear it!

[organ]

Awesome! That looks like a lot of fun to build. Glad to hear it's working out with your amp and maggies. Keep those tubes rollin!

Tour,
Man, if those circuit boards are freaking you out, why don't you send me your ST-70. I don't think you should be using an amp with an exposed circuit board. Trust me, I'll take good care of her:).

Maurice

[Tour2ma]

Maurice,
Pseudo inside joke...

At Troy's PF his CJ pre bit me when I was moving it. Ol' thumb got a little too close to the incoming 110 V termination...

Just tingled a little...

[madmax]

Originally posted by Tour2ma
At Troy's PF his CJ pre bit me when I was moving it. Ol' thumb got a little too close to the incoming 110 V termination...


The 400 volt line would have been more fun...

madmax

[BlueMDPicker]

As previously posted, I decided to mod all my Transcendent gear with blue LEDs, for power on indication. DAMN! The completed rig looks exceptional while listening at night.

But, what I really wanted to share here are the results of playing around a bit with the dropping resistor for the replacement LEDs on the power amps. The voltage source for the amp LEDs is one of the power supply caps @150 VDC. To use the 5V, 30ma LED I decided to go with required a 4.7K/5W resistor. I had a couple of 47K/5W resistors in the junk box, and decided to play around a bit. What I ended-up creating was an "automatic" bleed resistor for the power supply. With no load on the amp (speakers disconnected) and power cord disconnected, the LED fades away and bleeds the power supply caps completely in about 10 seconds. Pretty handy for those of us who like to open the hood and dabble!

Mike

[DAGLJAM6]

BMDP,

Just a quick question (I'm seriously considering moving the purchase date up on this pre ) Mike, did you do the attenuator upgrade or stay with the stock setup?
If every thing works out i'm shooting for mid june on acquiring
this pre ( in kit form ,a first for me) and may have a few more questions on a few mods/upgrades later.

Dave

[hotwheelman]

Originally posted by Tour2ma
Pre's with their tops popped make me nervous....

Nice...

Well at least you did not do what my wifes uncle did tonight on my town and country minivan, he helped with an install of a new coil pack, wires and plugs. He then decided that he would like to unplug one of the wires on my new coil pack just to see if he could do it, all I heard for the first two seconds was the electric pulses and then followed by " Owe... you goda** bi***!! I thought I would laugh my effin ass off. What makes it even funnier is that I was in the van when he did it and I could hear it from inside the van. His hair should lay down sometime this week.:D

[faster100]

Originally posted by BlueMDPicker
As previously posted, I decided to mod all my Transcendent gear with blue LEDs, for power on indication. DAMN! The completed rig looks exceptional while listening at night.

But, what I really wanted to share here are the results of playing around a bit with the dropping resistor for the replacement LEDs on the power amps. The voltage source for the amp LEDs is one of the power supply caps @150 VDC. To use the 5V, 30ma LED I decided to go with required a 4.7K/5W resistor. I had a couple of 47K/5W resistors in the junk box, and decided to play around a bit. What I ended-up creating was an "automatic" bleed resistor for the power supply. With no load on the amp (speakers disconnected) and power cord disconnected, the LED fades away and bleeds the power supply caps completely in about 10 seconds. Pretty handy for those of us who like to open the hood and dabble!

Mike


I did this with my power supply for my sonic impact and it bleeds the cap in a minute or so... so i dont have stored voltage hanging around.. the amp bleeds off the caps also from the led i installed in it.

[BlueMDPicker]

Originally posted by DAGLJAM6
Mike, did you do the attenuator upgrade or stay with the stock setup?
If every thing works out i'm shooting for mid june on acquiring
this pre ( in kit form ,a first for me) and may have a few more questions on a few mods/upgrades later.

Hi Dave,

Actually, I did neither. I had some Noble tapered pots and rotary selector switches here for a guitar amp I'm designing. I used them on the GG preamp. I think his stepped attenuator upgrade is a pretty good buy and should work nicely as well.

It's a very transparent and dynamic pre. I think you'll enjoy it a lot.

Mike

[organ]

Tour,
Ouch! That must have hurt. Good thing it was on a pre.

Mike,
That's great. Big caps really scare me. I drain each section of the quad cap in my ST-70 3 times just to be sure.

Maurice