A world class volume control for pennies on the dollar
teajayFor a balanced go this, https://goldpt.com/sa1x.html and use these with it for RCA input and or outputs when needed. Available at most Electronic shops https://www.jaycar.com.au/3-pin-xlr-type-to-rca-adaptors/p/PA3802 https://www.jaycar.com.au/3-pin-xlr-type-to-rca-adaptor/p/PA3800 Cheers George |
This product seems to be an active buffer with an Alps potentiometer for volume adjustment. I suspect there are op amps that provide unity gain but I cannot find any pictures of the internals. IME, a well-implemented buffer typically sounds better than an unbuffered volume control, particularly in maintaining tone and dynamics. If you want a remote volume control they offer the Elector analog preamp for about $2K more. However, it would seem feasible to utilize the same powered potentiometer that is used in the Elector to offer remote volume control in the smaller Volume 2 unit. I like that it is balanced and I would be interested in knowing more about the active components. |
@dgarretson That is sort of like my Metrum Adagio where the pot controls the reference voltage. @teajay I did go to the site and must have missed the 6moons review but I see it now. They always have the best pictures. I really like how they will not review something unless they can post pictures from under the hood. I will have to take the time to read the review - I didn't realize this has been out there for 10 years! Seems like maybe a good alternative to basic resistor volume controls like the Goldpoint and Endler attenuators I own. I wonder if there are better op amps that could be used now. |
The SPL Volume2 (and Volume8) have balanced in/outs. However, the input buffer converts to single-ended, the potentiometer is a single line per channel and the output buffer creates a balanced output. https://www.audiosciencereview.com/forum/index.php?attachments/_32a6963_1004-jpg.38139/http:// |
yes, like kr4 said, this
SPL Volume 2 is basically a preamp with only a single input/output. There are two monolothic op amps internally with a smallish normal linear power supply. Nothing special here in my opinion. It's likely good for the money. If you want a low cost active XLR preamp, it's probably a good deal. I'm not sure how you can do even a balanced preamp with only two op amps and a single-ended ALPS potentiometer. It's probably using one op amp as input buffer to convert to single ended, then routing through ALPS pot, then using the second opamp to just create an inverted signal from the potentiometer. I suppose it works, but you really want two opamps on the output for stereo balanced signals. It's more expensive, but the Wyred 4 Sound STP-SE is supposed to be a passive/active design. It's supposed to work as a passive circuit until the signal needs active gain (i.e. depending on signal level and input impedance of the amp its driving). A cheap solution would be to look for a used Rane MLM82a stereo line mixer. These are fully balance inputs, fully balanced outputs, and use a single-ended internal volume control. They are cheap at under $100 typically and still use a linear power supply. You'll need to get an XLR-to-TRS cable for the inputs, but it's cheap. Not sure how this compares to SPL Volume 2. |
Not a bad idea, as achieving good CMRR would be difficult with a balanced pot due to variations in tracking across four sections.@dgarretson Actually if you have a balanced control, even if it does not track perfectly, its a lot better than applying a single-ended signal if the input is balanced differential (as is the case with most opamps). It would have to be well off before you would notice the gain difference. The reason the Volume2 does the conversion to single-ended is based entirely on price point. |
Hello @teajay In your review of the SPL Elector and two SPL amplifiers you were impressed with their "overall silky-smooth presentation...grainlessness,,,balance where all frequencies are woven together in a natural, seamless manner...and great overall macro-dynamics"I am curious whether the comments above also describe the Elector preamp on its own, or only when used with the amplifiers, and whether the Elector preamp offers the same musical capabilities you described in your OP above for the smaller Volume2: "It is a pure conduit at passing on the upstream gear’s tonality/colors, dynamics, and spatial qualities. It has a vanishing noise floor, that allows micro-details to pop out to be easily heard."I am also curious about specific design differences that may affect any sonics between the Elector and the Volume 2. I am having trouble deciphering the specifications as to the amount of gain provided by each of the SPL preamps. The specs for the Volume 2 report gain as: "∞ bis -4dB." The specs for the Elector discuss the output level (max. output level 32,5 dBu) but do not specifically provide a value for gain. From the literature, I also cannot determine whether the Volume 2 uses their high voltage VOLTAiR 120V technology that is used in the Elector. Any insight you can provide about the gain and sonic differences between the Volume2 and Elector would be appreciated. BTW, let the folks at ST know that some of us appreciate photographs of the gear internals (as provided by one of the other pubs). |
Hey mitch2, Here's some information that hopefully will be helpful to you; 1) The Volume2 does not use the VOLTAiR 120V technology found in the Elector preamplifier. I'll still stick with my statement that Volume2 offers tremendous performance for the money. However, the Elector goes to another qualitatively level of performance across the board. As I stated in my Stereo Times review this preamplifier will compete with anything on the market and only retails for around $2000. 2) I have tried the Elector with numerous Solid State and tube based amplifiers. With all of them the results were superlative. The descriptors I used in my review are taken to all the other none SPL amps by the Elector when inserted into my different systems. 3) If you just Email SPL regarding the specs you are seeking regarding gain, I'm sure they will get back to you quickly. Address it to Hermann, head engineer. |
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@teajay Knowing you’ve used the Elector with both tube and SS amps to great results is very good news to me. I’ve been searching for more reviews of the SPL Elector and haven’t seen a great deal. But have been assuming it’s excellent just the same and this confirms. I’m still, however, getting advice to mix/match tubes w/solid state, but keep coming back to the clean/quiet/dynamic/refined thing that the Elector seems to offer. I’m looking to drive a GoldNote PA-10. |
