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From an old TT to a new computer, by way of an interesting preamp...how to go?

dilettante

dilettante

Well-Known Member
In my case the old TT is a Technics SL-QD33 I bought new 32 years ago. But the question would apply to any TT without a built-in preamp and/or built-in USB port.

I have a historically interesting central preamp with two built-in phono stages that I want to use in the path. It lies within the case of an old Hafler DH-101, but the electronic guts were built into it by Frank Van Alstine in the very early years of his current company Audio by Van Alstine (AVA). In those very early days of AVA, they didn't contract for their own component cases but rather built their own electronics into the cases of cast-off Hafler and Dynaco kit cases. I got this several years ago on Ebay and sent photos of the interior to AVA to see whether it was indeed their work, and Frank himself wrote back to confirm that it was. He also strongly advised me to roll the opamps with some more contemporary Burr-Browns. Frank said IC quality goes upward rapidly over time, and that the preamp would be comparable to their own contemporary ones if I did this. So I did. The phono stages are very nice now, and I want to use them rather than some other external phono preamp. The preamp has two pairs of tape-record jacks that are line out prior to any mixing or equalization done by the preamp, and right now I suspect they are the best route out of the preamp on the road to the music computer for recording the vinyl.

The thing is, I'm very new to digital audio and music computers. So I don't know the correct path from this goofy but tasty preamp to the computer. The computer is mini-ITX and so has just one pcie slot already occupied by a jcat femto usb card to feed a DAC. So I can't add a sound card. The mobo has onboard audio and the usual trio of 3.5 mm audio jacks on the rear I/O.

Although there may be better paths (please tell me if you see one), I now imagine two:

(1) This is simple but has a potential downside. Get a decent RCA L/R pair to 3.5mm stereo plug cable and feed the tape-record outputs of the preamp directly to the line in jack on the rear I/O. The downside is that the onboard audio probably has a mediocre A2D converter.

(2) Purchase or build a good quality external A2D converter with a USB digital output. Feed the tape-record outputs of the preamp into it, and feed the USB digital output of the converter into a USB port of the computer.

I'm more comfortable with route (2) in principle but am having trouble finding an external A2D converter (RCA L/R pair in, USB out) that doesn't look like a toy and is not terribly expensive,,, and would really like to hear about options if you know of any.

Also, if you think I've excluded another possible path that you think would be better, please say so. I'm thinking about buying a contemporary TT with USB output and retiring the Technics but the latter is like an old friend at this point. And any such new TT has to have a built-in A2D converter I would pay for anyway.
 
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Not sure that a modern table with an on-board preamp and A2D would actually be an improvement. Most of the tables with USB connection just aren't all that special, and I'd wonder about the quality of the electronics.

honestly I'd probably be more inclined to use the on-board sound vs swapping to what is probably a lesser table and RIAA stage. I've used the ones on my computer for this sort of thing and it worked fine, but I wasn't doing anything particularly critical where the ultimate sound quality was of any concern.
 
dilettante: Well, you could always try the first variant first, as it never harms to have a 2x RCA to 3.5 mm stereo cable at hand - but as you're already suspecting, the recording side of modern HDA onboard sound hardware typically still is the weaker side, whereas playback may already be pretty ok.

For the second option the question would be your definition of "terribly expensive", but if you'd really like to record directly with a computer (*) in really good quality, I'd suggest to consider one of the comparatively priceworthy, but pretty good prosumer USB sound interfaces like for example the Focusrite Scarlet 2i2 (currently 3rd gen.). The usual disadvantages of these are, that the input gain/level controls typically are separate (one knob per channel), which some people don't like, and that these prosumer models typically sport balanced combo (= both XLR and TRS) jack inputs, so that you need either commercial/ready-made or self-made RCA to T(R)S adaptor cables (**), while the outputs typically are TRS only.

Greetings from Munich!

Manfred / lini

*) Personally I prefer using one of those little digital field recorders (e.g. Sony PCM-M10, Roland R-05...) for recording to recording with a computer.

**) Self-made preferable. Because the commercial/ready-made ones most typically are RCA to TS only - whereas with self-made ones you can also go for the preferable configuration RCA signal (= center contact) to TRS tip, RCA ground to TRS ring and shield to TRS sleeve only (= single-sided shielding) in combination with a cable with two inner conductors plus shield, with which one is less likely to run into ground-loop hum problems.

And before you'd ask, why not RCA to XLR: Well, on some of those prosumer interfaces, the XLR part of the combo jacks is for microphones only, while the TRS part is for line-level & "hi Z" sources, so RCA to T(R)S is the safer/more universal choice, due to being suitable for both models with and without such a fixed jack assignment.
 
@gadget73. Yes, I agree with your observation that the A2D in some contemporary TTs might not be very good. The computer motherboard has a Realtek audio codec of some sort (as many motherboards do) and your recommendation does encourage me to try the first route (which is also the "thrifty" and simple route). Thank you.
 
I use a Parasound Zphono USB (discontinued) for this purpose. Besides the phono input, it has two other inputs - I run the preamp out on a Parasound P5 to one of those inputs with the USB out to my PC.

You may be able to find a used Zphono USB for a pretty good price.

Alan
 
@lini. Thanks a lot for your observations which, as usual, are to-the-point and constructive. I have looked at the HRT linestreamer (some AK folk seem to like it) and bumped into the Focusrite Scarlet 2i2 during that search. I'll take a look at your third route (Sony PCM-M10 or Roland R-05 or similar) as well.

As one of my Econ grad school buddies quipped, "Money isn't everything, but it correlates with everything." He was joking about big-picture (macro) Econ. But the same applies to my personal spending. Which is to say, I'm flexible about spending when there's some (subjective) substantial advantage to it.

@abpeep. I will also look at the Parasound Zphono USB. Thanks!
 
@lini. There are currently several very good deals on the Focusrite Scarlet 2i2 3rd gen on Ebay. I want to make sure I understand your (**) endnote. Does this mean a pair of two conductor cables, each ending with its own TRS 1/4 plug, that would each go into one of the two input jacks on the front of the Focusrite?
 
Hey dilettante, here's what I do. Manfred's suggestions also point to this method above and I think it is a good choice for a host of reasons.

I procured a Tascam DR2D (discontinued, new model available) and hooked that up to my tape out on my preamp. The signal comes in to my preamp from the phono stage and is recorded to an SD card which I can then take to either of my computers, my desktop (usually happens there) or my laptop to display the recorded file. I have Goldwave, an editing program, that I can then do what needs to be done (file splitting to separate out the tracks, volume changes, pops and clicks removal etc. etc.).

One obvious advantage of this is that the SD card has the recorded file that can be stored somewhere else (a large hard drive on my desktop, e.g.) or taken with me wherever I want. Another is the ADC, a very competent one that the Tascam has onboard as well as the ability to record in several resolutions (44/16, 96/24) that to me, when using e.g. the 96/24, sound better than the CD quality 44/16. On stuff I really like, I'll record in 96/24 (I have not been able to discern a clear advantage of 192/24 recorded on a DV-RA1000HD over 96/24 on the DR2D) and bite the bullet in terms of the larger files. Most stuff, in fact, I'll record in 96/24 and then down-sample it to 44/16 if I want to put the music on my phone, which has storage limitations (128GB) and it still, to me, sounds better this way than just recording in 44/16 from the start.

Anyhow, this gives you some ideas on how to proceed and keep what you like, just adding a component with which to make your captures at far better quality than the motherboard audio you might otherwise be stuck with.
 
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@Fishead. Thanks very much for this expansion on the "third route" @lini mentioned in passing. The details you give help me understand the what and why. I'm very grateful to you for it.

@vinyldavid. I do recall seeing other warnings about Behringer amongst the AK folk. As far as budget goes, I tend to think in terms of objective cost vs subjective benefit instead (as I mentioned in a reply to @lini above). I think benefit in audio is deeply subjective since hearing varies across people. It's one reason I have doubts about objective measurement protocols for audio as they overwhelmingly (always?) hinge on average treatment effects which ignore the heterogeneity of ears across listeners.

Currently I'm thinking I would like to spend under $300 solving this, but I've already revised upward to that number, and could do so again given good pointers on potential benefits.
 
Thanks, dilettante......I had to go back and edit a bit in my post as now I remember that the DR2D does not record in 192/24 but my friend's DV-RA1000HD does, and those recordings were compared and I concluded 96/24 is really the resolution that threads the proverbial needle for me.

Really liked your response to vinyldavid, by the way, and think you are absolutely spot-on.....hearing does indeed vary widely. This is why it's so important to find something that works well for YOU! The little Tascam, aside from being very budget-friendly ($199) produces a recording that I really like and puts a smile on my face.

I haven't done much recording lately, life getting in the way and all, but I have a very nice condensed library on my phone that I enjoy going down the road.....the occasional click and pop adds to the feeling that I'm listening to records.....which I am, just a little digital step in between but executed very faithfully to the vinyl "master." MoFi, you listening???:D Sorry, couldn't resist!!!
 
dilettante said:
@vinyldavid. I do recall seeing other warnings about Behringer amongst the AK folk. As far as budget goes, I tend to think in terms of objective cost vs subjective benefit instead (as I mentioned in a reply to @lini above). I think benefit in audio is deeply subjective since hearing varies across people. It's one reason I have doubts about objective measurement protocols for audio as they overwhelmingly (always?) hinge on average treatment effects which ignore the heterogeneity of ears across listeners.

Currently I'm thinking I would like to spend under $300 solving this, but I've already revised upward to that number, and could do so again given good pointers on potential benefits.
Click to expand...

I think that the radically different hearing and auditory processing acuities between listeners (even outside of raw frequency response) is a vastly under-researched topic. Products being designed to cater to those with "perfect" hearing are my own ideal, though I am sure there are some response deviations in my own head by this point. Objective measurements against a known flat input signal are a critical tool in judgements when auditioning isn't possible-it's very possible to have a device that sounds subjectively good but has .1% distortion, but one with .005% distortion is likely better. I don't fetishize microscopic differences in distortion (say, .003 to .005%), but it's nice to know what the test gear says.

For those who require certain gross frequency response or phase aberrations, deciding what nonlinearities they prefer is important, but so few did this, and wind up listening to Altec VOTTs or Klipschorns and have no idea why. Getting into higher end audio as a teenager, I quickly learned the wide variety of listener preferences and how important it is to protect one's hearing. One local fellow had Klipsch RF7s and a rotating selection of tube gear until he got fancy hearing aids, and then switched over to a Threshold Pre/Power and Thiel CS3.6. Funny how that works sometimes.

All that aside, I have two recommendations for a USB A/D converter of reasonable quality under $300.

My professional background is in classical recording, archiving, live musicals, and other audio adventures, and I'm pretty fanatical about digitization.

1) at $179, the Focusrite 2i2 is about the cheapest thing on the market that offers acceptable performance:
https://www.sweetwater.com/store/de...rite-scarlett-2i2-3rd-gen-usb-audio-interface

2) the SSL2+ is a nice step up. https://www.sweetwater.com/store/detail/SSL2Plus--solid-state-logic-ssl2-usb-audio-interface

If it were me, I would get the Focusrite and try to buy a record cleaning machine of some sort, a used Nitty Gritty may only push the budget over $300 by a bit, and having mechanically cleaned records is a HUGE improvement. I would also make sure that you have the best cartridge you can afford on your table. If memory serves, it's a P mount device, and finding good P mount carts is impossible these days. Only the cheap Audio Technica bodies with a number of esoteric aftermarket stylii remain as a viable option.
 
dilettante said:
Does this mean a pair of two conductor cables, each ending with its own TRS 1/4 plug, that would each go into one of the two input jacks on the front of the Focusrite?
Click to expand...

Yes, exactly. Those inputs are balanced and thus have three contacts (per plug type, so actually six for a XLR plus TRS combo jack) - one for the regular signal (+), one for the inverted signal (-) and one for the shield ground. And hence also my suggestion for self-made cables, 'cause the optimal configuration for unbalanced RCA to balanced TRS or XLR is RCA signal to balanced +, RCA ground to balanced - and the cable shield only connected on the balanced side to shield ground. Iirc, I've once seen a vendor on eBay offering that style of RCA to TRS cable, but the usually offered style is RCA to TS, so that RCA ground would go to both balanced - and shield ground, so that the chance of running in to ground-loop hum problems is higher.

That's also a reason, why I like recording with one of those little digital field recorders: One can record quite a few hours with a set of NiMH rechargeables, so that integration into an existing stereo system without introducing another ground is no problem at all - and hence the chance of thereby introducing a grond-loop is pratically zero. And two more advantages in my view are, that one doesn't have to worry both about optimal software/driver/operating system configuration for recording and about future driver support.

Greetings from Munich!

Manfred / lini
 
I disagree with the avoid Behringer statement, my UMC202HD has performed flawlessly for years and makes 24/192 recordings that sound as good as the ones I made using the PSAudio NuWave Phono Convertor I had for nearly a year, I'm using the Audible Illusions built in phono-stage (which is great), I use the Tape Outs to an RCA/1/4" cable to feed the Behringer and an Audioquest Coffee cable from the UMC to my computer. I use the Vinyl Studio software, worth it over any of the free things, and I have played the recordings through both my Chord Qute and the Gustard X-16 and whatever is on the record is what you get on the digitized copy.
 
@vinyldavid. Thanks for those suggestions. It's been a long time since those velvet cylinders people used back in the 70s, for sure. I hadn't given today's record-cleaning any thought at all. Your observation about the limits of the p-mount on the SL-QD33 are correct and I may spring for a new TT anyway.

You and I are using different technical languages, and so I misled you. When I referred to "objective measurement protocols" I meant something different from how I think you read it. I was talking about controlled experiments where listeners hear both A and B and decide whether they differ, or one is preferred to the other, and then a statistician compares these responses (which are subjective) to a hypothesis that, on average, there is no difference in these subjective decisions (that's an "average treatment effect" based on "within-subject treatment variation" in my technical language). I suspect you meant something like that (ask listeners whether A differs from B, maybe whether one is better than the other) when you used the term "auditioning." For a living, I do research on subjective judgment and decision, mostly about economic alternatives rather than hearing, vision, and the other sensory things that launched the field called psychometrics about 150 years ago (which was the first experimental psych as we know it today). And my particular bag is the heterogeneity of people. Hilariously, I sometimes forget that default technical language is heterogeneous across people too.

@lini. Thanks for clarifying what you meant. It makes perfect sense to me now. No, I have not solved the problem. After some discussions, tech support at the motherboard maker wants me to send them the board (and the RAM and CPU) for further diagnosis. But I'm committed to the mini-ITX form factor, whether with this board or another, which limits me to one low profile pcie slot as far as I know.

@RickB. I'm with J. S. Mill on this matter: Dissent is an excellent thing! Thanks.
 
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vinyldavid said:
If memory serves, it's a P mount device, and finding good P mount carts is impossible these days. Only the cheap Audio Technica bodies with a number of esoteric aftermarket stylii remain as a viable option.
Click to expand...

@vinyldavid, and everyone. I have seen adapters available for p-mount tonearms that claim to open up all of the 1/2 inch cartridges. But I also notice that p-mount TTs frequently (always?) have a pre-set anti-skating for p-mount cartridges. Is that right and, if so, does that negate the utility of these adapters? I'm not sure but would appreciate some edumacation on this.
 
@HungryEars. Thanks for this suggestion. Is your idea that it's better to write directly to an optical disc (and then I guess use the computer's optical reader to read it in) than to convert to USB and send that to the computer? Edumacate me.
 
dilettante said:
@HungryEars. Thanks for this suggestion. Is your idea that it's better to write directly to an optical disc (and then I guess use the computer's optical reader to read it in) than to convert to USB and send that to the computer? Edumacate me.
Click to expand...

The Tascam has a professional grade Analog to digital converter and will also do double duty as a high end player or cd transport. I think it will be just as easy to copy it directly to disc....But also it might have the function of sending the signal out through the digital coaxial without righting the disc directly to the computer.

I was looking at its multi functional and long term practicality and price point.

also lets you record directly the way you want out your already preamps without adding any new gear that has one function...for just a little more than a phono with a cheap analog converter you can get a professional grade analog to digital cd recorder....once its on CD its as good a digital as you will get through anything else shooting way above its price point.

once you got the CD easy to load to cpu.

IDK seems to simplify the process to oldschool ways.....you can play the record and adjust the input levels on the fly physically.....when I recorded vinyl to tape years ago on high end pioneer gear, it made all the difference in the finished product.
 
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