How Difficult Would it be to...
Jan 19, 2004 at 11:27 PM Thread Starter Post #1 of 21

bhjazz

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Convert an amplifier, say maybe a PPA, to something like the balanced mode that the Blockhead offers? I imagine replacing the single output to two outputs, and modifying the headphone cable to have two plugs. Maybe a ground lift switch like on the blockhead. I just see the shared ground path as possible noise source.

Then again...I could be nutso.
 
Jan 20, 2004 at 3:10 AM Post #3 of 21

andrzejpw

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It's really not that simple. The way the blockhead works is that there are TWO amplifiers, one per channel. So you're essentially building two ppas, one for the left side and one for the right. If you're doing this right, you also have two power supplies.
 
Jan 20, 2004 at 3:12 AM Post #4 of 21

braillediver

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If you're in Seattle? PPl the designer of the PPA is just over in Kirkland I believe. Why not drop him an email and discuss it?

Might as well go to the source since he's local?


Mitch
 
Jan 20, 2004 at 5:07 AM Post #5 of 21

bhjazz

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No kidding? I had no idea they were so close. What is the name of the company? Is it just PPI?

Thanks!
 
Jan 20, 2004 at 11:54 AM Post #6 of 21

BANGPOD

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bhjazz --

Quote:

Originally posted by bhjazz
Is it just PPI?


His name is PPL, not PPI.
smily_headphones1.gif


BANGPOD
 
Jan 20, 2004 at 5:09 PM Post #7 of 21

bhjazz

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Thanks for that informative answer. That clears it all up.

Does anyone have real contact information?
 
Jan 20, 2004 at 5:45 PM Post #8 of 21

Edwood

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Yes, it would be two mono amps. (bridged?)

The Blockhead is kinda silly if you ask me. Two volume knobs? C'mon. For that price one would expect something that was a bit more than just two amps linked together with front and rear bezels. It just feels DIY. Although some DIY is far better than factory built.

-Ed
 
Jan 20, 2004 at 7:09 PM Post #9 of 21

andrzejpw

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Two volume knobs is "DIY?" You seem to be misunderstanding the whole point of the monoblock design. By having one volume knob and combining the two amps, you're missing the whole point.
 
Jan 20, 2004 at 7:36 PM Post #10 of 21

bhjazz

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andre is getting warm....

Any amplifier we use is going to be stereo, which means we already have both channels we need. It seems entirely possible to modify the single headphone output to be two outputs, one from each channel. I know this is not a monoblock design. What I thought would be a nice idea would be to split the outputs inside the amp before the common ground point at the output jack. Then have TWO output jacks, and a simple modification to the headphone cables.

This is just theory, and the reason I did not post on DIY. But maybe I'll throw something out there, too.

By the way, any contact info for PPL in Kirkland? Thanks!

bhjazz
 
Jan 20, 2004 at 10:48 PM Post #11 of 21

NetRunner

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But they would still share the ground. That would be just a regular stereo-amp with two mono outputs. Only benefit could be in the different headphone cable required, but that is doubtfull.. ? No? Where you thinking something else?
 
Jan 21, 2004 at 12:28 AM Post #12 of 21

Swampwalker

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Balanced circuitry is different than monoblock or more properly dual mono construction. Dual mono is close to two monoblocks physically strapped together. A balanced circuit is very different from that and is not just dual monos with an XLR connector. Do some searching on AA or Audiogon under true balanced or differential circuits and you will find a detailed technical explanation.
 
Jan 21, 2004 at 12:53 AM Post #13 of 21

jefemeister

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Quote:

Originally posted by bhjazz
andre is getting warm....

Any amplifier we use is going to be stereo, which means we already have both channels we need. It seems entirely possible to modify the single headphone output to be two outputs, one from each channel. I know this is not a monoblock design. What I thought would be a nice idea would be to split the outputs inside the amp before the common ground point at the output jack. Then have TWO output jacks, and a simple modification to the headphone cables.

This is just theory, and the reason I did not post on DIY. But maybe I'll throw something out there, too.

By the way, any contact info for PPL in Kirkland? Thanks!

bhjazz


You're won't get any performance increase by doing this. There is only one ground in the system you just have it on two different cables. And this doesn't constitute a balanced system. If you're confusion comes from needing balanced operation explained, I will be happy to help out.
 
Jan 21, 2004 at 1:01 AM Post #14 of 21

xtreme4099

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they have their site for ppa's laroccoaudio.com just drop larry an email ... and he'll give ya some pointers, larry is phil's partner an does excellent casework as well, so if you want your ppa and want it pretty, drop them a line.
 
Jan 21, 2004 at 6:46 AM Post #15 of 21

Edwood

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Quote:

Originally posted by andrzejpw
Two volume knobs is "DIY?" You seem to be misunderstanding the whole point of the monoblock design. By having one volume knob and combining the two amps, you're missing the whole point.


Yeah, well I suppose you could use a pre amp to control the volume with one knob. But unless you have the stepped attenuator Blockhead, it would be a real pain to turn each knob at the same level for them to be balanced left to right (unless the pots are "notched" or something). It's just lazy design to me. Especially for their price.
rolleyes.gif


I guess I'll have to try the Blockhead myself sometime. I guess for many the poor user ergonomics of simple volume control can be overlooked for amazing sound.

-Ed
 

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