Why no Spectral phono stage?

You seem to be implying that there was another reason given that you doubt. What was that?

A Spectral dealer told me they did, but this was about a year ago.

Some of their older preamp models provided optional built-in phono stages, but I am not aware of any separate phono stages they have produced. And I believe that those built-in phono stages provided somewhat lowish gains, that were only suitable for use with LOMC cartridges by virtue of the relatively high gain provided by the line stage in those preamps.

Just guessing, but perhaps one reason they apparently have not produced a separate phono stage might be that application of their ultra-wide bandwidth philosophy and circuit expertise to a phono stage might result in significant design challenges related to avoiding RFI (radio frequency interference) issues, given the very low signal levels that are involved. And also given that the frequency response of LOMC cartridges typically has a resonant peak somewhere in the RF part of the spectrum, resulting from the interaction of cartridge inductance with phono cable and load capacitance.

I don't doubt that they could have overcome those challenges if they chose to, but perhaps they felt that it wasn't worth the effort given the competitive landscape.

Regards,
-- Al

There will be a phono preamp this year; it's been in development for over a decade, and rumor has it the specs and sound are extra-ordinary as usual. Suggest you join the Spectral forum at whatsbestforum.com

Al, the forum would also welcome your technical expertise and in-depth understanding of fast, wide-bandwidth designs used in the Spectrals

Given Dr. Johnson's role in digital recording technology, (HDCD, etc.) perhaps focusing on analog playback strategically isn't of interest to Spectral.

Cheers,
Spencer

Ack, thank you. My knowledge of Spectral's designs is limited to what I've read at their website and in reviews. You may find the comments by me, Atmasphere, and a number of others in this thread to be of interest, if you haven't seen it already.

An excerpt from one of my posts in that thread dated 2-6-15:

... slew rate, risetime, and bandwidth will in the case of many designs extend well beyond the point of being overkill with respect to effects that may have DIRECT audible significance. The Spectral amplifiers being extreme examples in that respect. As I'll get into in a moment, though, that does not necessarily mean that the only benefit is to those who write marketing literature....

So why have I put the word “directly” in caps? Well, I would presume the designers feel that by designing ultra-fast circuitry they can avoid or minimize effects which may be audibly significant. For example, they may be able to realize the benefits of increased amounts of negative feedback while avoiding or minimizing what would normally be its adverse effects, such as transient intermodulation distortion. Or the higher speed circuitry might help to minimize crossover distortion, or the effects of unwanted energy storage in devices, etc.

So what can be said about that? Well, it’s an approach, and a philosophy. As is usual in audio, how good or bad the results are will depend on quality of implementation, system matching, and listener preference.

In the case of their power amplifiers, my speculation would be that the main contributor to the subjective perception of speed that is generally attributed to them is the avoidance or minimization of TIM (transient intermodulation) distortion that might otherwise be a consequence of the use of negative feedback. Rather than the perceived speed being a consequence of the ultra-wide bandwidth in itself. Reduced TIM means "cleaner" transients, and it would seem expectable for that to correlate with subjectively "faster" performance.

Designs having ultra-wide bandwidth have their potential downsides, however, certainly in terms of additional challenges that have to be faced in the design process. And perhaps also in terms of additional challenges that might have to be faced by the user, to the extent that there may be increases in sensitivity to RFI, speaker cable capacitance, AC power quality, etc.

The potential benefits of their ultra-wide bandwidth approach seem to me to be mainly applicable to power amps, though. I'm not sure what the benefits of ultra-wide bandwidth might be for preamps or phono stages (as opposed to bandwidths of say 200 kHz or thereabouts, that being a factor of 10 greater than the supposed upper limit of human hearing, and therefore arguably high enough to eliminate the possibility of audibly significant phase shifts). But I don't doubt that with sufficiently good engineering excellent results can be obtained for those kinds of components with their approach, while also being obtainable with other approaches.

Regards,
-- Al

Hi Al,

yes, I followed that thread back then, and this is why I thought I would point you to whatsbestforum.com. In fact, I referenced some key posts of yours in a related thread there - see http://www.whatsbestforum.com/showthread.php?16704-Spectral-2000-3000&p=304684&viewfull=1#post304684

I happen to be very technical as well and can appreciate truly well-founded claims, and yours are at the top. The forum could really use your technical expertise, plus I find the discussions overall to be very high quality (Ralph is active on it too)!

Thanks very much, Ack, for the nice words both here and at the other forum. And for the invite to join there. I'll have to pass on it for the foreseeable future, though, as I'm probably already devoting more time than I should to my participation here :-)

Thanks again. Best regards,
-- Al

It's been over 2 years since these posts. Any word on a Spectral Phono Preamp? I love my DMC-20 Phono Stage, and it's still one of the best I've heard, but I'd really like to upgrade to a stand-alone phono preamp that does that plus more.

Dear @ctlphd : You own one of the best ever phonolinepreamp and I know exactly why you are satisfied with.

Up-grade to a stand alone phono stage. ?. I know that the DMC 20 was developed many years ago but you can be sure that its design and quality implementation is second to none. Prof. Johnson is really special.

Some active/passive parts were custom made for Spectral in your unit and if you look at his today Preamp or Amplifier you will see and understand what I'm telling here.
I listened Spectral many times and I like it but in those old times and maybe today I never had the money to buy it.

In the other side maybe there is no single stand-alone PS that can beats the Spectral phono stage module in overall way it does not matters how much you pay for it.
Additional to that with a stand alone unit the signal will be degraded at highest levels than in your unit because the signal coming from the stand-alone unit has to pass through additional cables, solder junctions and several connectors.

Maybe you can find out a better option looking for a new Phonolinepreamp that you can test in your system before buy it.

Unfortunatelly Spectral is a low profile marketing manufacturer and its products are so advanced that only a few audiophiles can really appreciated.

Spectral is a TRUE reference in audio electronics and not as other designs that in its advertasings speaks of " reference ". 

Spectral is the mark/challenge for any electronic audio designer.

I never heard/listen something bad coming from Prof. Johnson: electronics, subwoofers, LP recordings, CD's, etc, etc.

Good you own it.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

I am a 20yr Spectral owner. Know of ack and WBF. Waited (6) months to receive my 30 SV preamp. Absolutely stunning performance for (7) days. Then the protection circuits locked up.
 I tried every recommendation that Alan Goodwin suggested (A standup Guy) sent 30SV back to factory for an expedited trip.

The 30SV would not play nice with my Manley Steelhead. Used my Pass Xono; same outcome.

 I have heard from the Spectral website, Alan Goodwin and acks comments that the new phonostage was coming.

 I waited for a Decade !!!

My last conversation with someone in the know stating it would arrive in April 2017.

Where is it??????

 I just plain got tired of waiting and have moved on. Alan Goodwin lost a 44K sale; Spectral lost a 20yr loyal customer.

For me; Vinyl, Tubes, Class A, and Room Acoustics Rule.

After reading the reviews, I acquired a Spectral DMC 6. I am most satisfied. Try to find one. It is a wonderful preamp with a sensational  phono section.

Ctiphd. I appreciate you want a phono pre upgrade. FWIW, as a Spectral owner with fussy ears (classical,jazz, solo instruments) I have found a significant, across the board improvement by adding an Equitech 2Q to my system. If you can audition one you might be pleasantly surprised. Regards, Pete