The Computer Audiophile Posted November 10, 2012 Author Share Posted November 10, 2012 Enough gentlemen. Feel free to start another thread to continue this discussion. Founder of Audiophile Style | My Audio Systems Link to comment
barrows Posted November 10, 2012 Share Posted November 10, 2012 My mention of switching losses was only in regards to the distortion spec of the Sowter transformer alone-meaning that the distortion for a finished product would be higher. Clearly any analog preamp is going to require some kind of switch to select different volumes, whether it be a resistive pot, sealed relays, FET based IC switches, or something as sophisticated as Shallco switches. Please do not put words in my mouth either-I have never claimed to be an "engineer" anywhere, neither do I "pretend" to be one. To be more diplomatic: the problem with any analog volume control is that good are expensive: really good transformers are very expensive, and they will be more so if one requires balanced operation and 1 dB or less steps at up to -60 dB of attenuation. Additionally, performance will be further degraded by the switches, and switch quality will come into play. The best affordable swiches are carefully selected sealed relays, but measurably better, are the very expensive Shallco switches. I would suggest that the "best" TVC might include very good transformers, like the Stevens and Billington units, switched by Shallco switches, but such a preamp, would end up costing in the $10K area or above, just by a quick look at the math. So, the TVC style units are still subject to same cost constraints which affect any analog volume control. If one was really looking for the best analog volume control on a budget (assuming that we understand passive resistor based units are unacceptable in most systems due to dynamic problems) I would suspect that one of the new MUSE resistor ladder ICs, in a dual mono configuration (bypassing the internal IC opamp) followed by a simple, discrete, output buffer would likely do the trick. This approach would avoid the high cost of transformers, and mechanical switches, and could be produced by someone like W4S for around $2K for a simple balanced unit with a good power supply. I woudl not expect something like this to equal a KX-R, or a TVC with really good transformers and Shallco switches: but it would avoid very expensive parts for only a very small compromise in performance, and could offer tremendous value. The MUSE VC chips are used in Jeff Rowland Designs $18K preamp, so I am assuming they are quite good from a sonic point of view. Considering the continuing, missplaced, distrust amongst some audiophiles of digital VC, I am surprised thta some do not make the above product... SO/ROON/HQPe: DSD 512-Sonore opticalModuleDeluxe-Signature Rendu optical with Well Tempered Clock--DIY DSC-2 DAC with SC Pure Clock--DIY Purifi Amplifier-Focus Audio FS888 speakers-JL E 112 sub-Nordost Tyr USB, DIY EventHorizon AC cables, Iconoclast XLR & speaker cables, Synergistic Purple Fuses, Spacetime system clarifiers. ISOAcoustics Oreas footers. SONORE computer audio | opticalRendu | ultraRendu | microRendu | Signature Rendu SE | Accessories | Software | Link to comment
barrows Posted November 10, 2012 Share Posted November 10, 2012 sorry Chris, can you move posts to a "how to control volume" discussion? SO/ROON/HQPe: DSD 512-Sonore opticalModuleDeluxe-Signature Rendu optical with Well Tempered Clock--DIY DSC-2 DAC with SC Pure Clock--DIY Purifi Amplifier-Focus Audio FS888 speakers-JL E 112 sub-Nordost Tyr USB, DIY EventHorizon AC cables, Iconoclast XLR & speaker cables, Synergistic Purple Fuses, Spacetime system clarifiers. ISOAcoustics Oreas footers. SONORE computer audio | opticalRendu | ultraRendu | microRendu | Signature Rendu SE | Accessories | Software | Link to comment
4est Posted November 10, 2012 Share Posted November 10, 2012 sorry Chris, can you move posts to a "how to control volume" discussion? For the record, the Bent Audio TAP uses Stevens and Billington transformers and sealed relays, and retailed for 2.5K. Similar items still sell for similar pricing and use nice switches. That was my original point. Sorry Chris! I do not care what you do with this volume control discussion. I just didn't want the TVC mis-information to go unchallenged in a thread where high end attenuation was an issue- possibly swaying one's purchasing decisions. If you or another were here, I could readily demonstrate the difference. I doubt anyone would be thinking about a "huge amount of distortion" as the low level detail and body are maintained while the volume gets lowered, as compared to the digital volume within my DAC (which just so happens to be much the same as Barrows'). Forrest: Win10 i9 9900KS/GTX1060 HQPlayer4>Win10 NAA DSD>Pavel's DSC2.6>Bent Audio TAP> Parasound JC1>"Naked" Quad ESL63/Tannoy PS350B subs<100Hz Link to comment
bmichels Posted November 2, 2014 Share Posted November 2, 2014 Anyone has tried the DAC2 X against the TAD DA1000 & the Berkeley Reference DAC ? They are all in the same price point... Link to comment
majnun70 Posted December 26, 2014 Share Posted December 26, 2014 OK. I have confirmation there will be a digital volume control in the DAC2X through firmware. That does it for me. I'm rolling the dice and am going all in. Any update on this? From whom did you get confirmation? Link to comment
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