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Doc B. · 19937

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Offline murray

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Reply #15 on: June 21, 2014, 07:01:03 PM
@Natural Sound:
Do you know how many watts you can get with the 12 volt supply?

Murray S. (N.Z.)


Offline Tubejack

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Reply #16 on: June 22, 2014, 04:56:19 AM

There are 10 types of people in this world,
Those that understand Binary and those that Don't!


Offline Natural Sound

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Reply #17 on: June 22, 2014, 11:07:02 AM
@Natural Sound:
Do you know how many watts you can get with the 12 volt supply?

No, I have no way of measuring that. The Bottlehead circuit is different from what I'm using so it's a moot point anyway.

.



Offline Paul Birkeland

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Reply #18 on: June 22, 2014, 12:21:13 PM
I'm sure that PB will jump in here and correct me if I'm wrong. The TPA3122 will run on 10 to 30 volts. Operating the chip at lower voltages will produce a little less power. I'm running a TPA3122 on a single 12 volt SLA behind a quickie. It sounds great in my shop where I don't require a ton of power.

Yes, this is true.  (The chip actually seems to run OK on 9V as well)

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Bonzo

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Reply #19 on: June 22, 2014, 08:24:29 PM
Will it be possible to use a (good) 18vdc switching psu?
Will this deteriorate sound quality too much?

Thank you

Bisogna avere orecchio!


Offline Paul Birkeland

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Reply #20 on: June 24, 2014, 04:07:15 AM
I suspect that the 18V switching supply will work, but that the sound quality will deteriorate greatly.

There are some good papers available online that go into what happens in a switching supply when you operate outside of the rated supply current.  Essentially, things are really bad at either end, and a Class D amp is going to run you into the low end and high end of current demand frequently.

-PB

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Bonzo

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Reply #21 on: June 27, 2014, 12:01:17 AM
I suspect that the 18V switching supply will work, but that the sound quality will deteriorate greatly.

There are some good papers available online that go into what happens in a switching supply when you operate outside of the rated supply current.  Essentially, things are really bad at either end, and a Class D amp is going to run you into the low end and high end of current demand frequently.

-PB
Got it!
What about input sensitivity? It would be lovely to mate it with a quickie, but I noticed chip amps needs attenuation rather than amplification of the input signal
PS:Any underside pics? ;-)
Ciao!

Bisogna avere orecchio!


Offline Paul Birkeland

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Reply #22 on: June 27, 2014, 03:42:01 AM

What about input sensitivity?

IIRC, gain is right around 20dB.  Since the Quickie isn't a particularly high gain preamp, they are a well suited match.

-PB

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Bonzo

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Reply #23 on: June 27, 2014, 05:16:42 AM
IIRC, gain is right around 20dB.  Since the Quickie isn't a particularly high gain preamp, they are a well suited match.

-PB

Thank you very much Paul!

Bisogna avere orecchio!


Offline johnsonad

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Reply #24 on: June 27, 2014, 12:50:41 PM
Nice one! I look forward to hearing it!

Aaron Johnson


Offline aragorn723

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Reply #25 on: June 30, 2014, 03:25:44 PM
How well would this amp do with 24V instead of 18?  2 12 volt SLAs would be a nice battery choice for this :)  I like my current SS power amp but this is kinda intriguing!

Dave



Offline Doc B.

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Reply #26 on: June 30, 2014, 04:45:47 PM
The amp will run on anything from 10 to 30 volts, just like it says a few posts up.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline satbaba

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Reply #27 on: June 30, 2014, 07:22:58 PM
Sennheiser HD800 compatible?
I'm still using crack OTL + speedball



Offline Paul Birkeland

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Reply #28 on: July 01, 2014, 04:50:43 AM

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Doc B.

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Reply #29 on: July 01, 2014, 05:00:06 AM
Thanks for all of the Quicksand orders the past 24 hours! The guys will be photographing the assembly today for the manual. We should have the oft requested underside photo very soon.


Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.