Blackmore Posted February 23, 2009 Report Posted February 23, 2009 I am not sure if I can post this, but here is the link to this article, which I found very interesting to read Stereophile: Tim de Paravicini: King of Tubes Now I am wonder what kind of balanced output configuration my Unico have, because of this: "Lots of people have made so-called valve CD players with a couple of token tubes. Most of them don't actually address the problem correctly, because a lot of them, if they're going to offer balanced outputs, actually go back into op-amps to do the balanced output configuration. So they've got this token tube doing not very much". Here is some article about Unico and how it works with output thing http://www.audioenz.co.nz/2004/unico_cd.shtml The signal travels through a gain stage with two 5814 tubes (a milspec version of the ECC82/12AU7, one per channel) and finally to a mosfet output stage with proprietary power supply and precision non-switching regulators which can handle voltage variations of up to +/- 20%, hence the need for a rear heatsink.
Guest sacd lover Posted February 23, 2009 Report Posted February 23, 2009 I am not sure if I can post this, but here is the link to this article, which I found very interesting to read Stereophile: Tim de Paravicini: King of Tubes Now I am wonder what kind of balanced output configuration my Unico have, because of this: "Lots of people have made so-called valve CD players with a couple of token tubes. Most of them don't actually address the problem correctly, because a lot of them, if they're going to offer balanced outputs, actually go back into op-amps to do the balanced output configuration. So they've got this token tube doing not very much". They did that with the Eastsound E5 too. They used a discrete output stage for the single ended outputs but implemented the balanced outputs with the addition of op amps .... thus deteriorating the sound quality noticeably vs single ended operation. Stupid huh?
Blackmore Posted February 23, 2009 Author Report Posted February 23, 2009 Ups, yeah, pretty... How do you like your Unico and which tube are you using at the moment. You did bought one, am I mistaking? They did that with the Eastsound E5 too. They used a discrete output stage for the single ended outputs but implemented the balanced outputs with the addition of op amps .... thus deteriorating the sound quality noticeably vs single ended operation. Stupid huh?
Guest sacd lover Posted February 23, 2009 Report Posted February 23, 2009 Ups, yeah, pretty... How do you like your Unico and which tube are you using at the moment. You did bought one, am I mistaking? The unit arrived dead (well it actually worked for a few seconds) so it was returned.
Blackmore Posted February 23, 2009 Author Report Posted February 23, 2009 Ahh, pity, its quite nice CD player, at least to try out. Do you think it have an real tube balanced output stage? Technically, I am not skilled at all. Which transport he had, TEAC or ASUS, like my. The unit arrived dead (well it actually worked for a few seconds) so it was returned.
tkam Posted February 23, 2009 Report Posted February 23, 2009 Open it up and take some close-up pics. That's about the only way we'll be able to know for sure what's driving the balanced outs.
Blackmore Posted February 23, 2009 Author Report Posted February 23, 2009 Will try upload tonight, thanks
deepak Posted February 23, 2009 Report Posted February 23, 2009 TdP "king of everything" ? I remember reading an article where he said he could make an SS circuit sound exactly like a tube one, but chose to use tubes because they were "in fashion"
aardvark baguette Posted February 23, 2009 Report Posted February 23, 2009 TdP "king of everything" ? I remember reading an article where he said he could make an SS circuit sound exactly like a tube one, but chose to use tubes because they were "in fashion" I remember this too. In my mind I recall it being that tubes were used 'for marketing purposes'. Kind of makes me doubt him, tbh.
Blackmore Posted February 23, 2009 Author Report Posted February 23, 2009 I hope this would help a bit, best I could do
aerius Posted February 23, 2009 Report Posted February 23, 2009 Sometime TdP does great work, sometimes I think he does things just because it's cool or because he can. The EAR Acute would be an example of the former, the V20, the latter. It's like hey, I bet I can make an amp that uses 20 12AX7's. I still don't get that, using 12AX7's as power output tubes.
Torpedo Posted February 23, 2009 Report Posted February 23, 2009 Blackmore, I find difficult to know if they're using every triode into the ECC82 for the output, so every tube can deal with both rails of the balanced path, or whether they're using just one triode and only one rail is "tubed". The late makes little sense, but who knows. I'm not sure at this moment if the SE outputs go tubed or not. Are they? In this case the whole balanced path could be not tubed and being fed by those 4 discrete transistors which we can see in your last pic, which are the same showed in the first and second.
Blackmore Posted February 24, 2009 Author Report Posted February 24, 2009 As far as I know, only XLR are tube based. What pics do you need more to get an idea?
Blackmore Posted February 24, 2009 Author Report Posted February 24, 2009 Here is the answer from Unison Research tech department. in UnicoCD we use a single stereo DAC with balanced outputs, the balanced signal goes to a hibrid (tube + BJT) differential stage that drives both XLR and RCA output.
Torpedo Posted February 24, 2009 Report Posted February 24, 2009 Does it have any selector to let the signal out to be only SE or balanced, or can you use both outputs at the same time? If you can use both outs at the same time the only "problem" with such circuit could be that the hot out in the balanced output, and the SE active would be "seeing" the input impedance of the two preamps/integrated/headamps you were using in parallel, while the cold rail of the XLR output would see just the balanced pre/amp input impedance. While this is quite a minor concern, it could have some audible consequences. To avoid this it would be advisable to use only either the SE or XLR outs and having only one pre/amp connected to the chosen one.
Blackmore Posted February 24, 2009 Author Report Posted February 24, 2009 You are quite right, I can not use both at the same time, even if I choose, using my EAR RCA/XLR selector, if two pairs of cable are connected its creates distortion, which dont make it possible to listen, so, I use only one at the time. And no, there is not selector on CD player, cos if it was it would be possible, I guess... THX Does it have any selector to let the signal out to be only SE or balanced, or can you use both outputs at the same time? If you can use both outs at the same time the only "problem" with such circuit could be that the hot out in the balanced output, and the SE active would be "seeing" the input impedance of the two preamps/integrated/headamps you were using in parallel, while the cold rail of the XLR output would see just the balanced pre/amp input impedance. While this is quite a minor concern, it could have some audible consequences. To avoid this it would be advisable to use only either the SE or XLR outs and having only one pre/amp connected to the chosen one.
Torpedo Posted February 24, 2009 Report Posted February 24, 2009 Well, not a big problem, just need to change wires
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