UGS adventures

[taoben65]

what is UGS

[CeeVee]

Universal Gain Stage .

[Thomas Giz]

Anyone having spare boards for UGS ?

[apassgear]

Originally Posted by thomashek

Anyone having spare boards for UGS ?

I might be able to help...PM me please

Tony

[nar]

I also have some spares, from our recently finished UGS project + UGS Motherboard

Best,

nAr

[nar]

Originally Posted by nar

I also have some spares, from our recently finished UGS project + UGS Motherboard

Best,

nAr

Now in da box n' playing nicely

Ladder connector detail

PSU-ombilical, need to build proper case

Best regards,

nAr

[ENSen]

I intend to use the Joshua Tree attenuator from twistepearaudio.com in front of the UGS pre. The standard resistor set that can be bought together with the attenuator gives an input impedance between 2,2 kohm and 10 kohm and an output impedance of 750 ohm. I bought the attenuator boards without any parts so I am free to chose the resistors to suit my needs. I am a little worried that 2,2 kohm would be a little low at the input of a pre. What do you think? Should I go for a little higher impedance?

[nar]

Originally Posted by ENSen

I intend to use the Joshua Tree attenuator from twistepearaudio.com in front of the UGS pre. The standard resistor set that can be bought together with the attenuator gives an input impedance between 2,2 kohm and 10 kohm and an output impedance of 750 ohm. I bought the attenuator boards without any parts so I am free to chose the resistors to suit my needs. I am a little worried that 2,2 kohm would be a little low at the input of a pre. What do you think? Should I go for a little higher impedance?

It might be problematic for your source. I mean, the Joshua model is designed to be placed at preamp output, not input. Standard sources won't like to be loaded with variable impedance and as low as 2,2k. For that reason at UGS input a fixed impedance attenuator of 47k or 50k is preferred.

You can keep the existing resistor values you have, and by placing attenuator at the output it would likely work and would be a better match; UGS won't mind the varying impedance of the ladder. A 10k fixed ladder might be a better solution at the output though.

UGS out impedance is about 125 ohms single ended and 250 ohm differential.

Best,

nAr

[ENSen]

Originally Posted by nar

It might be problematic for your source. I mean, the Joshua model is designed to be placed at preamp output, not input. Standard sources won't like to be loaded with variable impedance and as low as 2,2k. For that reason at UGS input a fixed impedance attenuator of 47k or 50k is preferred.

You can keep the existing resistor values you have, and by placing attenuator at the output it would likely work and would be a better match; UGS won't mind the varying impedance of the ladder. A 10k fixed ladder might be a better solution at the output though.

UGS out impedance is about 125 ohms single ended and 250 ohm differential.

Best,

nAr

You are probably right, I should put the attenuator after the pre.

I will start with these boards since I already have them but later I may try a 10K ladder as well.

Thanks for the answer.

[nar]

Originally Posted by ENSen

You are probably right, I should put the attenuator after the pre.

I will start with these boards since I already have them but later I may try a 10K ladder as well.

Thanks for the answer.

It will work at the output

For ladder at the input input I mounted two of those for balanced operation in stereo, so far so good :

http://www.audiophonics.fr/potentiom...0k-p-5228.html

Best,

nAr