Utc A-20 and Triad A67J
Does someone know about those transformers? Those vintage units should do the job but I'm not sure.
Does someone know about those transformers? Those vintage units should do the job but I'm not sure.
Re: Utc A-20 and Triad A67J
UTC A-20 should be great. Someone here in this thread is using them.
I have a pair of UTC HA-108 and they are great. UTC stuff in good.
crazyfrog said:
UTC A-20 should be great. Someone here in this thread is using them.
I have a pair of UTC HA-108 and they are great. UTC stuff in good.
I have the UTC A-20 and love them. I have not experimented too much with loads and filters so cannot recommend values. I have a pair of Edcor 10k:15 I bought for another purpose that I might try if I get some time.
The Triad A67J was primarily used for inputs so they might not be robust enough. If you can get them dirt cheap they would be worth trying. The A20s were industry standard for many years and have a great reputation.
Best, Bill
Best, Bill
I tried a pair of Jensen JT-123-S I got off Ebay. Not the best of the Jensens by any stretch, the Sescoms are far superior IMHO. More bass reach, much better soundstage layering.
I bought a pair of UTC A-43 transformers. These have a single 600 ohm (150 ohm split) primary and two 600 ohm (150 ohm split) secondaries.
What would be the best way of wiring the secondaries for single ended output? I could use one secondary and ignore the second, but would it be better to parallel the secondaries or do something else?
I don't need any voltage gain.
What would be the best way of wiring the secondaries for single ended output? I could use one secondary and ignore the second, but would it be better to parallel the secondaries or do something else?
I don't need any voltage gain.
To be truthful I never thought of paralleling the two secondaries, as my Sescoms have two secondaries also. Just using one set works great. I did try them in series and didn't like the pseudo increase in dynamics, sounded like a processor. Try it any way,you never know.
Best, Bill
Best, Bill
Can someone here assist me understanding the sequence of events that takes place between 3 sources please.
Setup:
CD transport, ps3, PC (does not matter) >>>External DIY DAC>>>>AV reciever/ AMP>>>speakers
Ok here is what I think happens.
CD player transfers the the Digital Signal in PCM format bypassing the CD players own DAC.
The external DIY DAC recognizes the signal as Digital currency and decodes the PCM to analogue then passes out through its analogue stage in to the receiver/amp.
The amp receives the signal in analogue format so bypasses/disregards its own DAC and passes the signal out its analogue stage to the speakers.
So am I correct that all the mods that are being done to the DIY DAC output stage , be it Op-amp, Tube, or tranni, is just really cleaning the Signal and probably boosting the signal?.
If so the most dramatic change to the characteristics of the sound will happen at the receiver/amp analogue output stage.
If I have this wrong please put me in my place, I have been looking in other threads but could not find anything to clear it up (just more of the same questions)
Thanks
Setup:
CD transport, ps3, PC (does not matter) >>>External DIY DAC>>>>AV reciever/ AMP>>>speakers
Ok here is what I think happens.
CD player transfers the the Digital Signal in PCM format bypassing the CD players own DAC.
The external DIY DAC recognizes the signal as Digital currency and decodes the PCM to analogue then passes out through its analogue stage in to the receiver/amp.
The amp receives the signal in analogue format so bypasses/disregards its own DAC and passes the signal out its analogue stage to the speakers.
So am I correct that all the mods that are being done to the DIY DAC output stage , be it Op-amp, Tube, or tranni, is just really cleaning the Signal and probably boosting the signal?.
If so the most dramatic change to the characteristics of the sound will happen at the receiver/amp analogue output stage.
If I have this wrong please put me in my place, I have been looking in other threads but could not find anything to clear it up (just more of the same questions)
Thanks
That is pretty much correct except we are trying to preserve the original signal as it was recorded, not actually clean it up. The amount of information on a CD or whatever you are using for the source is pretty amazing, but every time the signal passes through any circuitry some information is lost, some is altered, and some is masked by noise. If your system is comprised of high quality analog equipment then the weakest link in the signal chain is always the analog section in your source. The digital section in an A/V receiver might have great specs, but that does not mean it will sound good, too many compromises.
That's my two cents.
Bill
That's my two cents.
Bill
I'll be waiting a little before I'm able to get trannies for this DAC. When it comes, will this DAC work with Poly caps in place of trannies for the time being?
My five cents:
Better use it in the beginning like you bought it.
And then switch to the trannies, and you will have an impressive experience, you will remember this moment many years later 😀
Franz
Franz Gysi said:
You are right, it is a remarkable, almost shocking experience.
A couple big caps with a 2k load might be fun to try but you should use a low pass filter of some kind for protection.
Bill
Cheers, guys 🙂
I do have a pair of trannies, but have to find out how to configure them as they are custom and do not have any indication as to what is what.
I'll get in touch with someone that knows them, and see how I go from that point.
🙂
I do have a pair of trannies, but have to find out how to configure them as they are custom and do not have any indication as to what is what.
I'll get in touch with someone that knows them, and see how I go from that point.
🙂
How big would coupling caps need to be if directly connected to the dacs outputs? I have four enourmous 100uF 1000V russian military paper in oil caps that could be used if suitable... I'd be connecting the dac to a preamp with a 10Kohm input impedance
McGyver said:
Nice job pal. You used tube buffer instead transformers, show me please the diagram and which tube you used.
Thanks