Eddie Current's upcoming SS amp called Red Top ?!

[purrin]

  Do you know if the 3-pin jack and switch he includes with the current amp production run is for accommodating the ±24 Vdc tube PSU when he makes it available?

 
Yes. That's what it's for. You can make your own bipolar PS or get the fancy tube PS when or if it is available. The amp does sound a little bit better with external PSU; but as it is with the power brick, it's hardly gimped at all.

 

[jacal01]

Do you have any listening impressions with it yet?  The BJTs make me think that it might have very good transient response and microdetail tracking.  It's not by any chance current driven amplification, is it?

 

[purrin]

Yes. Impressions are scattered out there. I'll cut and paste them into HF when I get a chance.
 
Definitely BJT sound. Really fast and clear. Yet organic / dark sounding. Not current driven.

 

[jacal01]

How it it for digititis, that is, fatiguing, that old SS glare syndrome?  By dark do you mean added color or texture (lushness)?

 

[purrin]

Dark tonality. Not bright. Not fatiguing. No glare. But sharp and articulate treble on the attacks - BJT like. By organic, not necessarily lush, but a bit of bloom. Almost tube like bloom in mids. Worked well with everything I threw at it recently: HD800 (stock), PM-2 (alt PM-1 pads), Paradox, Abyss.

 

[jacal01]

Thanks, purrin.  What's the closest amp comparison, in your experience?  Its biggest shortcoming (other than PS)?  Do you admire it, personally?
 
I only ask because I'm pulling the trigger on one.  Looking to replace my desktop Soloist, which is the poster child for glare, IMO.  Do you happen to know when its production run is scheduled?  I should be asking Craig, I know, but once he gets a whiff of a stupid or ignorant question, he's gone, incommunicado, like a trophy trout spitting out a fly... 

 

[purrin]

I'm scratching my head trying to think what would be a close sounding amp. I mean, not many organic sounding solid-state amps around if you know what I mean? Maybe the Bakoon current mode amps? The #1 shortcoming would be lack of ultimate resolution. I think Ragnarok, Krell Klone, maybe even GSX2 are better at picking up low level information. #2 would be inability to differentiate small changes in volume - the microdynamics are not as good as better tube stuff out there (and this is only if you believe tubes are able to do this better than solid-state). It's hard to bitch at $800. 
 
I can see people not liking the BJT sound since so much other stuff is FET and/or MOSFET. I can see people preferring something brighter for a solid-state amp (for reference, the Red Top is less bright than the 4-45 or Mjolnir.) It does seem sensitive to DACs, so that is either a good or bad thing.
 
I just wanted a simple no fuss amp that didn't heat up the room with an tonal presentation akin to the other EC amps for relative cheap. I plan on getting one for my desk at work since the ECZD would be ridiculous (and probably dangerous too - I think the burn scar on my forearm is no longer there from the 6C33C-B)
 
Yeah. I get you on the communications with Craig. Mine usually run a bit differently:
 
"Hey Craig, I get a lot of noise when I use the AD2000s and turn the volume knob up half way."
 
"What do you expect? The AD2000s are really sensitive and will pick up noise. You will destroy your hearing if you turn up the volume knob that much with the AD2000s."
 
I bring amp in to him. He acknowledges: "Oh man, I would be pissed. This is really noisy."
 
Anyways, I need to pick up and drop off some stuff to him this weekend or maybe early next week. I'll find out when it will be available for shipping. I would expect sooner than later because its on a PCB rather than the point-to-point wiring jobs on the big tube amps.

 

[jacal01]

That's both good and bad vs. the Bakoon.  The HDA-21's full bodied sonics is a hearty recommendation, but now my expectations for clarity, space and fidelity have been also raised, so that I might be disappointed with the RT's analogous performance.  But as you say, at its price point there's bound to some compromising in comparison.   I mostly want something that I can listen to for extended periods while I'm working that doesn't inevitably start becoming strident and fatiguing to my ears.  Something smooth and mellow and faithful that plays in the background would suit me just fine.  And I'm not just talking volume control.
 
But that does bring up a point.  I've noticed with some amps that the music takes on a sort of veiled (~smothered) loss of detail at lower volumes.  I realize that we're not working with a whole lot of resolution to begin with for this amp, but have you notice any progression in this effect at the lower registers with volume decrease?
 
I think I lost Craig when I didn't pick up on the "two high frequency fly back supplies" on his power board that he threw out into the conversation.  Nothing interesting here to talk about, Johnny, move along...  I think that he's just tired of explaining his work to the unwashed ignorant just to make a sale.  Hand holding tedium, as it were.  You either want it or you don't.  At least that the impression I get from him going in.   And all of this just from being ignored.  

 

[purrin]

I actually feel it's better than Bakoon. Better control, separation, precision, delineation,and speed than Bakoon. Hard to say for sure without a direct comparison. It depends upon what you are looking for. I guess you can say Bakoon is more lush. Red Top is more bloomy. Words are tough to use tiodescribe and sometimes they may be completely misunderstood.
 
On the power supply, the board as a high frequency charge pump (http://en.wikipedia.org/wiki/Charge_pump). Basically converts DC 12V from the switched brick to +/- 24V. Any external supply would bypass the charge pump to the power rails directly. Probably a less complex explanation.

 

[BournePerfect]

Thumbs up, Marv!! Thumbs WAAAAAAAY up!
 
I need an RT.

 

[jacal01]

  I actually feel it's better than Bakoon. Better control, separation, precision, delineation,and speed than Bakoon. Hard to say for sure without a direct comparison. It depends upon what you are looking for. I guess you can say Bakoon is more lush. Red Top is more bloomy. Words are tough to use tiodescribe and sometimes they may be completely misunderstood.
 
On the power supply, the board as a high frequency charge pump (http://en.wikipedia.org/wiki/Charge_pump). Basically converts DC 12V from the switched brick to +/- 24V. Any external supply would bypass the charge pump to the power rails directly. Probably a less complex explanation.

 
Better than the Bakoon?  Hmmmm...  We'll see.  But that's encouraging, to say the least.
 
Now, see?  That's just why he's still talking to you. 

   But the charge pump somehow compromises the signal so that bypassing it directly with an external ±24 Vdc power source maintains signal integrity better?
 

Originally Posted by BournePerfect /img/forum/go_quote.gif

I need an RT.

 
Yeah! A refreshing RT cola to really hit the spot!  

 

[purrin]

The original prototype just had this huge honking linear power supply. No charge pump circuit on the original board.
 
I can only guess that the charge pump circuit (really just a DC to DC) was added for the following reasons: 1) keep the overall footprint small without the need for a huge outboard power supply; 2) allow flexibility with the use of a small power brick that could take voltages from 100-220; 3) keep costs down. So yes, it was a compromise.

 

[jacal01]

Anything short of a step-down transformer/rectifier is a compromise, evidently.
 
But that means that the original prototype support battery was something like a 24 V military/aviation type, without the charge pump in place?
 
Another thing I got no answer on from Craig is how big does he expect his future ±24 Vdc tube PSU package to be; would it still be in the desktop (if not transportable) range, do you think?  Are you able to anticipate its size, based on what you know about the requisite circuitry?
 
And WTHI Marv? 

 

[purrin]

This was the makeshift original power supply. The Teac DAC is being used as a placemat for it.
 

 

[jacal01]

I got shivers going thru me just looking at it.  Big fat transformer, alright, and I'm not yet seeing any tubes. Looks like I'm going to have to jettison at least a couple of piles of paper off my desk just to make room for it, if this is any indication of things to come...
 
I can hardly wait.