It can be, as can any analog preamp of/or from any time period/model/design/etc.

The question is how complex the job, will it compromise sonics and what will it cost?

The parts can be purchased for about $100 or less, but placing that gear in the preamp, and doing the music service instead of harm, is the rub. And the tech doing it for you needs to be an AUDIOPHILE and ANAL..all at the same time. We can be painful to deal with.

It might be done for less than $200, but figure that as being the 'base-floor' cost structure for such a mod.

http://cgi.ebay.com/ALPS-IR-Remote-Volum...Q2em118Q2el1247

http://cgi.ebay.com/Hi-End-Volume-Contro...Q2em118Q2el1247

The correct value of resistance for the given preamp's volume control must also be the one selected. The correct unit must also be available.

Also consider that the complexity of the circuitry and board added can also degrade the sonic qualities of the given preamp or circuit..as well as the power supply characteristics needing to be added to the SP-6, via addition of an extra power supply,and this includes a transformer and rectification. I suspect (IIRC, from seeing pictures of an SP-6)the chassis has room for such an addition, but as stated, the whole thing would bottom out at the $200 mark for such a mod, and go up in price from there.

I just looked, the space is VERY tight on the SP-6, for this particular remote volume kit. Others are available, but are all generally the same in sizing...

Likely $250, to do it right.

Dumping the SP-6 and moving on to something from the ARC range that has what you want, might end up being the way to go.

Call Audio Research with your question. You can always buy a line level control unit with remote and use it as the master pre amp with the SP6 serving as a slave used for switching and signal processing. If you'll place something on the oder of "remote control potentiometer" in a search engine you should find repalcement volume controls that could be retro-fitted to your pre amp. Then you'll either have to perform the job yourself or find a tech willing to take on the task. Remote source selection is not as easy.

Normally you would run whatever sources you wish into the SP6 and then take its tape out feed into any line input on the remote control unit. This would keep the volume control on the S-6 out of the loop. Every source plugged into the SP6 would then be heard on, say, the "CD" input on the remote control unit. If you purchased a line level unit that was sufficiently transparent to replace the SP6 on all but phono, you could run your CD and other line level sources directly into the new unit. In any case the remote control unit would be directly in front of the power amp and after the SP6.

An alternative approach would be to advance the SP6's volume control to full which would essentially take it out of the circuit as far as impedance and level matching for the new control unit. You would then take your feed off the SP6's pre amp output and run into any line level input on the remote unit. There are some problems with this scheme, the first being anyone else in the house who might not catch on to the new arrangement. Too many places to control volume is not a good way to set up a system. The other problem would be potential mismatches between the output level and impedance of the SP6 and the input impedance and overload level of the new unit. This would simply be a matter of selecting the correct device for your installation.

In KBK's approach, if you can't retro fit the remote vc into the SP6, you could set up the remote volume control (with its attendant power supply - which you could probably construct out of batteries for less noise) in an outboard box and run the remote volume as a single input passive pre amp of sorts. There are also a fair number of just such devices already on the market - place "passive pre amp" into a search engine. This would minimize any problems the vc might have on the performance of the SP6. In this set up you would run the output of the SP6 from either tape out or pre amp out as described above. All source switching would be performed manually at the SP6 and the passive vc should be configured as any other passive pre amp with attention paid to cable length and input/output impedances. If you're not sure about passive pre amps and the restrictions, place "passive pre amp" into Stereophile's search engine and read what's required to get the best out of a passive device. Remember you'l need a new set of interconnects to go between the SP6 and the passive device.

Whichever route you take it will be somewhat of a kludged together system and you might want to consider a new remote control pre amp with the performance level and warranty of a current production model. Yet another route is to sell your pre amp on Audiogon and look at what's available there as a replacement.

http://buy.audiogon.com/cgia/fsb.pl

Only you can tell what will influence the sound of the final product. Listen with the Mac in line and out. Try running the output of the SP6 through the "tape in" jacks of the Mac. There is typically less circuitry involved with tape loops than any other input. Along that same line of thought, try running your CD player through the "tape" input of the SP6.

The SP-6 has within it's gutty-whuts..a very good volume control. Equaling it in quality is going to be difficult.

As of recent, just the past few weeks, I've been running a outboard MM/MC unit into a passive preamp, and running all my line level stuff into the passive pre. I get all the volume I'll ever need. I did go through the trouble of putting a stepped attenuator directly into the highly modified MM/MC box...and then ran that straight into my power amp. No active volume amp, just pure 'passive' controlled level for the phono box, right into the power, with no extra cable of any kind.

The scenario of a CD player with a volume control running right into a power amp, but in this case, Phono! Wow. I'm getting an extra layer of signal that I was not even aware was there (ie, recorded) on about 1/3'rd to 1/4 of all the records I'm playing. My usual preamps are things like highly modified MFA, Counterpoint, etc kind of gear, so I'm down to the point that I don't think it's possible to hot rod it any better or shorter 'path' than that..other than building the phono pre right into the power amp and losing that IC cable as well. What I'm saying, is that I'm noticing the degradation brought to the table by $5k-10k-20k preamps. Anything in the path degrades. It's a question of how much it bothers the given person, or if they even notice the degradation, as few understand the degradation brought by even one interconnect. But it's there. You just have to learn how to sonically/mentally 'sort it out'.

The point of mentioning all this, is that any extra cables and boxes/devices -will- degrade your signal quality. It all depends on how important such things are to you, or rather..how much the given level of degradation will affect your listening, over that convenience which the given outboard remote volume might bring.