[nebulus]

I'm thinking to build phono stage and headphone amplifier. I chose qsxm3 as phono stage. It has quite impressive psu. Phono stage operates from 15V. For heaphone amp i am going to build dynalo. Dynalo operates from 16V. Is it possible to make dynalo operate from 15V? (i could use the same psu for both

)

 

[bg4533]

The Dynalo will work just fine on +-15V. The voltage is close enough that you do not need to make any changes for bias or anything.

 

[Garbz]

Indeed this will bias it slightly higher but that will not be a problem. The other compromise is tweaking the pre and running that from 16v It looks like it will probably work.

 

[bg4533]

Quote:

Originally Posted by Garbz Indeed this will bias it slightly higher but that will not be a problem. The other compromise is tweaking the pre and running that from 16v It looks like it will probably work.

The PSU he wants to use uses 7815/7915s to put out 15V. Going to 16V will require some changes to that PSU.

Does anyone have any comments on that PSU? A lot of people really don't like the 78xx regulator for some reason. I wonder if you might be better off going with a PSU like what is used in the Dynahi. At the very least variation in the PSU should be less. The Dynahi PSU will probably cost more to implement though.

 

[dgardner]

Quote:

Originally Posted by bg4533 The PSU he wants to use uses 7815/7915s to put out 15V. Going to 16V will require some changes to that PSU.Does anyone have any comments on that PSU? A lot of people really don't like the 78xx regulator for some reason. I wonder if you might be better off going with a PSU like what is used in the Dynahi. At the very least variation in the PSU should be less. The Dynahi PSU will probably cost more to implement though.

The Dynahi and Dynalo amplifiers derive some performance benefits from tracking regulators. With tracking regulation, whatever happens on the positive rail, happens equally and oppositely on the negative rail. The 7815 and 7915 are acceptable regulators, but when used alone togther do not form a tracking circuit. The Gilmore style PSUs use a reference voltage and a pair of power op-amps to form a tracking circuit. Nice, but cost more money.

The HeadAmp Gilmore Lite uses the 7815 and 7915 in the wall wart version without tracking and many people really rave over it.

 

[dgardner]

Quote:

Originally Posted by bg4533 The PSU he wants to use uses 7815/7915s to put out 15V. Going to 16V will require some changes to that PSU.Does anyone have any comments on that PSU? A lot of people really don't like the 78xx regulator for some reason. I wonder if you might be better off going with a PSU like what is used in the Dynahi. At the very least variation in the PSU should be less. The Dynahi PSU will probably cost more to implement though.

The Dynahi and Dynalo amplifiers derive some performance benefits from tracking regulators. With tracking regulation, whatever happens on the positive rail, happens equally and oppositely on the negative rail. The 7815 and 7915 are acceptable regulators, but when used alone togther do not form a tracking circuit. The Gilmore style PSUs use a reference voltage and a pair of power op-amps to form a tracking circuit. Nice, but cost more money.

The HeadAmp Gilmore Lite uses the 7815 and 7915 in the wall wart version without tracking and many people really rave over it.

 

[skyskraper]

fixed voltage regulators, in real terms i doubt you're going to notice a difference with them vs say LM317. its a lot more convenient to have one part vs a whole heap of different ones on hand for building though

 

[Garbz]

they don't like the LM series because they can be outperformed. But by what really? I mean my LM7809 and 7909 give me exaclty the same noise reading as running from 2 9v batteries on the output. Most probably thanks to the PSRR of the opamps but still.

If you need a real regulator Jung Super Regulators are pretty much the be all and end all.