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Balanced Input Options

Mike a balanced input transformer may be the way to. I don't think these take anything away from the sonic footprint

There was a review on an English made passive preamp which was basically a resistor ladder for volume plus a transformer.


One thing the reviewer noted was that the pre took out the digital harshness he sometimes got after long listening sessions. He didn't think the sound quality was lost in any way in fact he found the overall musicality was improved. I don't think the resistor ladder had anything to do with it, it was all down the transformer

have a look and see what you think
 
And of course balanced xlr to unbalanced xlr is also a viable option. So XLR sockets on the pre straight into the avondale amplifier boards. Make sure the the XLR cable is correctly earthed of course for this configuration to minimise noise transfer.

I use this on my Atom HE. On the Atom balanced outputs do have a lift in SQ over the phono outs but my Avondale inputs of course only have an unbalanced input. Whether I would get a further lift by installing say the neurochrome boards I don't know but my gut feeling is not.
 
OzBrit Audio said:
On the Atom balanced outputs do have a lift in SQ over the phono outs but my Avondale inputs of course only have an unbalanced input. Whether I would get a further lift by installing say the neurochrome boards I don't know but my gut feeling is not.
Click to expand...
My gut feeling is that you would
 
PigletsDad said:
Transformer is the easy way to do this. Jensen JT 11p-1 would be a very good choice, but about £80, so not cheap. As you only need a 1:1 transformer, lots of problems cancel out, so a cheaper part would only be a mild compromise. Something from Edcor would do, and would be about US$26.
Click to expand...
Any idea why Cinemag recommend their 10:600 transformer, with a shunt resistor?
 
OzBrit Audio said:
And of course balanced xlr to unbalanced xlr is also a viable option. So XLR sockets on the pre straight into the avondale amplifier boards. Make sure the the XLR cable is correctly earthed of course for this configuration to minimise noise transfer.

I use this on my Atom HE. On the Atom balanced outputs do have a lift in SQ over the phono outs but my Avondale inputs of course only have an unbalanced input. Whether I would get a further lift by installing say the neurochrome boards I don't know but my gut feeling is not.
Click to expand...
Are you using pins 2 and 3 as pos/neg (with double signal voltage)?

Or are you using 2 and 1, leaving 3 floating?
 
Mike Hanson said:
Are you using pins 2 and 3 as pos/neg (with double signal voltage)?

Or are you using 2 and 1, leaving 3 floating?
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The second one, pin3 floating using mogami cables. I tried shielding both sides and ended up connecting on the source XLR side. These cables are short less than a metre

But in the end I use some Chinese clone Cardas Cross cables which are far superior to the Mogami ones I made up.
 
Have a look at this thread for ideas, though it's mostly SE input to the amp.......

Phase splitter choices on input of PP amp

I'd like to know what are the choices for a phase splitter on the input of a PP amp so it could be driven by a preamp with gain using RCA inputs. Amp in question is an EL84 in PPP triode, so 8 output tubes in all. Choices I can think of include.... input transformer like 1:1+1 or 1:2+2 solid...
www.diyaudio.com www.diyaudio.com
 
I ran an Avondale amp from the Balanced out of a Audiolab DAC for years by just connecting up the plus and ground sides
of an XLR socket on the amp.Only downside is reduced signal level but if
the system has enough gain no problem.
No reason to put stuff in the signal path
if you don’t need it.
 
GWM said:
I ran an Avondale amp from the Balanced out of a Audiolab DAC for years by just connecting up the plus and ground sides
of an XLR socket on the amp.Only downside is reduced signal level but if
the system has enough gain no problem.
No reason to put stuff in the signal path
if you don’t need it.
Click to expand...
You connected the +ve to ground? Isn't -ve conventional? Any idea on the attenuation level?

Thanks
 
Dan K said:
You connected the +ve to ground? Isn't -ve conventional? Any idea on the attenuation level?

Thanks
Click to expand...
Doesn't really matter as long as both channels are the same as it is just a phase inverted copy of the other one. You wll lose 3dB so it effectively doubles the noise floor.
 
Whether grounding one leg of a balanced source works acceptably depends upon the nature of that source. If the source is an output transformer then there is merely a loss of 3dB of signal. Actively balanced sources are not always so forgiving. One example that I have in front of me here, a Topping D10 Balanced DAC, should not have its balanced output partially grounded unless you want a pretty dramatic increase in distortion. If I recall correctly the vast audio distribution setup of the BBC WS in the 90's in Bush House was based around actively balanced 300 Ohm sources and Transformer Balanced destination equipment, often travelling through many 100's of metres of balanced audio cable in between with remarkably little loss of quality.

John
 
Dan K said:
You connected the +ve to ground? Isn't -ve conventional? Any idea on the attenuation level?

Thanks
Click to expand...
No connected + side of the balanced out to
+ in on the amp, the common zero connects to ground on the inlet, the negative phase on the balanced out is
left unconnected.
 
That way you dont get any common mode DC cancellation. Depending on the source that could be a real problem. My DDDAC has 2.69v DC bias between the balanced outs and ground. If I just dropped the cold the amp would not like it but adding cold to ground cancels that out.
 
That’s a lot, if you’re talking about DC offset
I measure 6mv max on my pre out so no issue I don’t even use a DC blocking cap on the input.
 
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