Yes, the paper tube is holding up the Regen - it didn’t really look like it needed it to me, but the guys from Uptone asked me to add some support (perhaps because they aren’t familiar with the JCat USB cable’s flexibility and weight.) I guess it’s a good thing that my wife made the paper tube to replace the stacked plastic cups we initially put there.
magicknow saidYup, no problem.Paul McGowan said one set of outputs,Paul can this output both be used at the same time? The balanced to feed the DAC and RCAs to feed a Sub?
Scott Hull of Part Time Audiophile took a series of great pictures of our show setup - the best yet.
http://parttimeaudiophile.com/2015/10/05/rmaf-2015-its-always-sunny-at-ps-audio/
Have a look!
Nice pics and write-up of the set-up. No mention of what it sounded like, though.
Paul McGowan saidBob said Paul, I really wish I could have been there! And... please tell me there's a line level (fixed) output on the new pre?Well, yes and no. You can assign any input to be fixed, line level out - like a home theater bypass. Hopefully that works?
I hope that the level is not 0dB. Then you might run into headroom issues especially if you route your LFE channel to your mains…
Paul, I just want to clarify a little. Perhaps it’s best to just tell you what I want to do. It’s two things. First, being a bit of a connoisseur of fancy headphone amps (got my eye on the new Berning now), I want to be able to take a fixed-level output from my pre so that I can play any source through an external headphone amp, and control the volume of that independently of the preamp volume (so I don’t blast the rest of the house when I crank my 'phones.) I have been thinking about the internal headphone jack issue, and the truth is that I sort of think that true headphone people are gonna usually go with a separate amp, no matter how great your headphone out is, simply b/c no one size fits all in terms of impedance, power, gain, etc. And most headphone people already have a head amp that they will simply want to connect to the output of the pre. So I think this is a very common need, and there isn’t really a satisfactory way to meet it without a fixed-level output - yeah, we could just switch off the power amp when listening to phones, and set the volume control on the headamp to max, but that’s clunky, and I hate clunky. Secondly, being married to a not-yet-audiophile, I also connect a preamp level output of my main system to an external multizone amp that powers a bunch of in-wall speakers. This is maybe not as common as an external headphone amp but I’d bet you’ve got a good number of customers who do stuff like this. Here too, it’s strongly preferred to feed the multizone amp with a fixed level signal, so if I want to crank the main speakers in the living room, it won’t blow my wife through the back wall upstairs, as her volume is controlled independently. Bottom line is that I think you will sell a lot more of the new pre if you can figure out a way to include this feature. To me, being short one analog input isn’t a showstopper b/c it’s easy enough to compensate for it, so I’d gladly trade one set of inputs for a set of fixed outputs. Thanks for listening!!!
Bob said ....To me, being short one analog input isn't a showstopper b/c it's easy enough to compensate for it, so I'd gladly trade one set of inputs for a set of fixed outputs. Thanks for listening!!!Agree!!
Thanks for the explanation and it makes perfect sense. Unfortunately, it’s unlikely to happen and here’s why. It just isn’t so simple as eliminating one set of outputs and replacing with another output, fixed or variable.
Imagine the circuit for a moment. After input switching there is a tube amplification stage connected to a MOSFET output stage. And when you look inside the preamp, which is stuffed to the gills, you’ll note the voltage regulation, tubes and MOSFET outputs take all available room just to make them work. This is not some IC riddled product, it’s the real deal.
Now, add to that the volume control itself. It is a combination of an input attenuator and a means of changing the gain of the vacuum tube. Both the attenuator and gain differences in the tube account for the differences in output gain.
How in the world can we give you a fixed output in addition to the variable one? It would require another tube and output stage - and that’s not going to happen - we can only fit one in there as it is.
In other words, there is no point in the circuit for a fixed output other than directly off the switched inputs, and before the input attenuator. But, let’s imagine we added a set of connectors attached to this point. Now the problem is two fold. We don’t have any amplification (it is before the tube) and we don’t have any output buffer. In other designs, engineers fix this very simply - they throw in an IC op amp and call it good. I would suggest this solution would not only sound poor, it is also not within keeping of the high standards we are going for with the BHK Signature preamp.
Hope that makes sense.
How about using a space saving line driver: Balanced line driver
I have seen this item used in products 3 times the price of the PS Audio preamp. I am not sure where to connect it though, and you need additional XLR receptacles on the back plate which render it impossible, I guess…
Paul,
I hear you and thanks for the explanation. So I guess what I can do is manage with my external headphone amp by turning off power amp and maxing the volume. I could go back to using the main preamp volume to power the in-wall system too, but having changed it to the way I have it now, I hesitate to go back. But there is another way: I can just build a completely separate server and system to power the in-walls. Which is not as much of a hassle as it sounds, b/c I always have plenty of spare machines, already have a passive pre and an old but rebuilt Superphon laying around, already have the amp of course, and can connect up my tuner with a y-cable to both systems. So that would actually cost me next to nothing, and I suppose it would also eliminate the sacrilege of connecting up your preamp to a cheaptastic multizone amp.
PS to the above: Paul, I believe you have addressed this before, but since I can’t find your previous comments at the moment: suppose I were to take the balanced outputs of my DS DAC and run them into my pre, and connect the RCA outputs of the DAC to a separate preamp. Is this going to lead to a decrease in sound quality, if I keep both sets of cables very short, and input impedances not crazy low? That would be one way I could simply add a 2nd preamp to my setup, in theory. But otherwise I can set up two separate systems, with a cheap DAC (of which I have plenty laying around, LOL) to feed the whole-house setup.
Bob,
I think PS Audio has commented that using both outputs of the DAC simultanously is OK, provided the issues you mention are under control. I tried it and didn’t like it. I wonder if the DS is extra sensitive due to its transformer output circuitry, but I am not sure.
Frode, thanks. I could install a switch for serious listening sessions, so I could disconnect the RCA outputs.
Bob, on a first test I connected my Sennheiser amp to the rec monitor outputs of my McIntosh pre C2300 (unfortunately only RCAs, not balanced).
On a second test, I connected the RCA outputs of the DS DAC to the unbalanced inputs of the Senn amp, and kept the balanced connection of the DS hooked to a balanced input of the Mc pre. Both connections were simultaneous but obviously not played at the same time.
I can tell you that I did not find any substantial audible differences among both. Regards, Ricardo
One issue you have to remember is that you unbalance the XLR when you connect the RCA also.
The output level of the XLR is +6dB compared with RCA when only XLR is connected.
Is this issue only a problem for dacs? I am also “mixing” outputs in my Oppo. They even recommend to use both rca and xlr outputs from the main channels simultaneously.
Paul McGowan saidThe equipment stand is a piece of furniture my son's custom woodshop builds - in the rear of the room there's a real credenza in the same style. There's a Power Plant P10 inside the stand, plus the Mac Mini. We wanted to get away from the traditional HiFi look this year, and try to go more in-home style.
hahaha, in a mad men, living/drinking at the office kind of look
Frode, as it happens I really would not want to lose that 6db… thanks!
ridom said Is this issue only a problem for dacs?No, any piece with both single-ended and balanced output can exhibit this behavior. It depends on how the output circuitry is designed.
Note that you are not going to hurt anything by using both on the DS, you just lose the extra 6dB balanced otherwise exhibits.
Got it. But since the DS has only one balanced output and my Mc pre has only an RCA fixed output (no fixed XLR) I have to trust on my headphone amp (used through its RCA inputs) to compensate this loss. The other way to do it is by connecting and disconnecting the XLR cable every time I use the headphones, and it’s really uncomfortable.