[The Monkey]

My B22 is full of teh awesome.

 

[penger]

Quote:

Originally Posted by danne /img/forum/go_quote.gif Anyone compared RSA Apache vs Beta22?

Compare side by side, no. But I have owned both at different points in time and I like the B22 more.

 

[LeMat]

After all the discussions, and while I wanted to stay away from the DIY world, I have been convinced this amp is a hell of a reference... so I'll take the plunge.
For the same budget I could have an SPL auditor but ... taking SPL + retailer mark-up into consideration, this shoulnd't be able to compete.

Just one thing I'm wondering. Should I go with a complete dual mono, meaning 2 distinct PSU line (twin sigma22) or a standard single one ? I have no clue what difference it can make...

 

[Steve Eddy]

Quote:

Originally Posted by LeMat /img/forum/go_quote.gif Just one thing I'm wondering. Should I go with a complete dual mono, meaning 2 distinct PSU line (twin sigma22) or a standard single one ? I have no clue what difference it can make...

Well, dual power supplies are typically used to help prevent interchannel crosstalk through the supply rails.

But if you build a "balanced" B22, the current draw from the power supply will be constant as long as you stay in class A (which you should for just about any headphone you plan to use with it), so there's nothing to couple through the supply rails, in which case dual supplies offer no particular benefit.

se

 

[LeMat]

Quote:

Originally Posted by Koyaan I. Sqatsi /img/forum/go_quote.gif Well, dual power supplies are typically used to help prevent interchannel crosstalk through the supply rails. But if you build a "balanced" B22, the current draw from the power supply will be constant as long as you stay in class A (which you should for just about any headphone you plan to use with it), so there's nothing to couple through the supply rails, in which case dual supplies offer no particular benefit. se

Thanks. But I aim at building a single ended B22 (will see later if I decide to go balanced), so would you recommend a dual PSU ? And if so, will it make a real difference or is it as "elusive" as burn-in and these kind of things ?

Mmmm I just found out this read....
http://books.google.ca/books?id=uET2...age&q=&f=false
may answer my questions

 

[Steve Eddy]

Quote:

Originally Posted by LeMat /img/forum/go_quote.gif Thanks. But I aim at building a single ended B22 (will see later if I decide to go balanced), so would you recommend a dual PSU ? And if so, will it make a real difference or is it as "elusive" as burn-in and these kind of things ?

Whatever benefit there might be with dual supplies I would expect to be marginal at best.

First, the o22 will keep the rails well regulated and provide a very low output impedance.

Second, when it comes to power supply rejection, the B22's designed rather like a guy in one of those bomb proof suits with every stage being cascoded which keeps it well isolated from the supply rails.

If it were me, I'd go with a single supply.

se

 

[LeMat]

Quote:

Originally Posted by Koyaan I. Sqatsi /img/forum/go_quote.gif Whatever benefit there might be with dual supplies I would expect to be marginal at best. ....... If it were me, I'd go with a single supply. se

That's what I tought and what I was expecting to read

Let's see what I'm capable of now !

 

[Steve Eddy]

Quote:

Originally Posted by LeMat /img/forum/go_quote.gif That's what I tought and what I was expecting to read Let's see what I'm capable of now !

Whether single supply or dual, take good care when it comes to grounding.

In the meantime, good luck!

se

 

[penger]

To my knowledge, you need two for occasional speaker duty. Otherwise, I believe one should be sufficient.