Preamp for audio research ref110

Hi, just purchased an arc ref110. My current preamp is an arc sp9 mkii. Unfortunately it doesn't have balanced outputs (why do they sell them like that? given that most of their amps need balanced). I am looking for a short term and long term solution. For the short term I would like to at least test the amp with a minimum of investment (as I need to wait until the purse reloads). So my questions are: is there anyway to use what I have for a while? And what would be a good longer term solution hopefully under 3k. And by the way I use records so I need a phono solution. Thank you all in advance. 
LOL, I bought a REF110 this spring and had the same surprise.  I ended up buying a LS17SE that is still breaking in.  Sounds amazing though!!
For short term you could run an RCA to balanced cable from the SP9 to Ref.110. If you have a good tech you can upgrade the SP9 way past a MK.111. The phono stage especially will be light years ahead of a Mk.11, the line stage pretty damn good as well. You could run the phono stage from the SP9 into another Pre-Amp if desired.

The best fully balanced Pre. I've heard for the money is the Vincent SA-T8, sublime. Compares to many Pre's 2 to 3 times it's cost. No phono stage though. Have just got a Doge 8, has balanced outs, but not fully balanced. You'd need to roll the tubes. The line stage sounds promising. I havn't used the built in phono stage yet. By all reports the MM stage is very good, but the MC is crap. What cart are you running?
Don't be too harsh on ARC, the SP 9 is an old "entry level" (for them) unit, built and sold back before ARC went all balanced with their equipment--that didn't start till they brought out the LS 5 (a terrific sounding line stage, by the way).  I'd go with later ARC preamps for the long term--the LS 16 was their first full-function preamp that had balanced outputs, as I recall, but it will sound different than the SP 9, which was less "tubey".  For the short term, initforthemusic has some good ideas, you might also ask ARC or a good tech if there's a way to give the SP 9 true or faux balanced outputs for your purposes.
For short term you could run an RCA to balanced cable from the SP9 to Ref.110.
I suspect that like most or all of the the more recent ARC Reference series amps the Ref 110 won’t work properly when provided with unbalanced signals via adapters or adapter cables. In the more recent designs, at least, apparently only half of the balanced signal path within the amp would see a signal in that situation, resulting in a drastic reduction in power capability among other consequences.

If ARC confirms that is the case with the Ref 110, what I would suggest is that you purchase a Jensen Transformer, probably their model PI-2RX (similar to the PI-2XX shown at the link except with RCA input connectors). Give Jensen a call to confirm that would be the best model to use in your specific application. It would convert the unbalanced signal for each channel to a true balanced signal pair. It would also eliminate any possibility of ground loop issues between the preamp and power amp, and would provide noise rejection comparable to the performance of a fully balanced interface. It would require that you use a very short length of XLR cable on its outputs (no more than about 2 feet or so), but the length of the RCA cables connecting to its inputs is not critical.

Good luck. Regards,
-- Al

For short term, IMO it's not reasonable to invest into Jensen Transformer. spending extra $200-ish, it's wiser to sell SP9 and get fully balanced preamp. There are active balanced converters sold by major pro-audio internet retailers along with B&H photovideo and J&R stores of Manhattan for much lower price point, but even that can wait till you get REAL stuff...

BAT VK3i normally with no phono, but VK installs phono-board there for $500 and it will be HUGE step above SP9.
Sell the SP-9 MK II.  You could get at least $800.

The Sp-9 MK II is from around 1990.

Buy a more modern preamp with balanced, or both single ended and balanced outputs.
I called ARC and they said RCA to XLR converters would not work, for the reasons almarg mentions, above.
Thank you all for the help. I think I will get an RCA to xlr converter until I get the real thing. Seems like these are available from pro-audio shops. 

Regarding the cart, I am using a simple shure m97xe
I think I will get an RCA to xlr converter until I get the real thing. Seems like these are available from pro-audio shops.
Given the previous comments by Docknow (thanks!) and myself, I assume you are referring to an active converter, i.e., one that contains powered circuitry. If so, a point to keep in mind is that like many and probably most ARC line stages and preamps the input impedance of the device to which the SP9 MkII is connected should be relatively high. From its description at
Recommended load 60K ohms and 100pF. (20K ohms minimum)
A lot of pro audio equipment will not meet that requirement, not even the 20K minimum.

A transformer-based converter, by the way, such as the Jensen I referred to earlier, will easily meet that requirement when used in conjunction with your particular power amp, and when used with many and probably most other amps as well.

-- Al

While my aesthetics Callisto pre eclipse was in for service (7 months) I bought an LS16 modes by Steve Huntley of the great northern sound co.  It was the same price as a new ls17 that I was lusting over, but I took a chance.  I was amazed at how good a $2k used pre could sound compared to my $6k aesthetics.  I have had the aesthetics back for a month and haven't bothered to hook it up.  BTW just run RCA, balanced just gives more gain that people like because they get more volume.  But that comparison is for another posting.  Although, if you have grounding issues, balanced does help.  For 2k you could also try the Ayre K-5xeMP for around - solid state but dead silent.  Just my 2 cents, ymmv - happy listening.
The Ayre is an excellent suggestion.

I have a Ref-5 and previously used it with a Ref-110. I now have a Ref-150, because I needed more power for power hungry speakers, but either way, the 2 are magical. I know it's more than you want to spend, but you can find good deals on pre-owned ones.
Having been in this hobby for years and having owned the same preamp, I am with the others that have recommended selling the SP9 MKII. I went from that pre to a SP14, to a LS25 MKII, to now a Ref 5SE. Each preamp changed has added more to my musical enjoyment. Once you switch over balanced you will be smiling constantly.
It's all good, but to me it's OK to live few days with unbalanced depleted signal. ARC preamps have very high line-stage gain so the volume won't be deficient at all till the other unit arrives.

As a possible alternative, I recommend my Modwright 36.5. I found it to be a little better than the ARC Ref 3 I compared it with and a good bit cheaper. Modwright kit is in general, excellent value. I find ARc Power amps more to my taste , than the Pre's. The combination of the Modwright and ARC Ref 75SE, is perfect for me.

if you are in the Los Angeles area, feel free to contact me.  I have two Jensen transformer devices that I'm not using that you are welcome to try out before you purchase one.

In the interim,  it is a very good way to go.  I bought them because I was using single ended out from my previous crossover to balanced in to my amps.  I then upgraded to a Krell KBX balanced crossover configured to work with my speakers and the need for the Jensen devices went away.

However, they work pretty good. 

Also, before you decide to get another full function with phono (I presume) pre-amp, I would first retube that SP9 MK II with new tubes.  I did that before and then auditioned a REF3 pre-amp side by  side (A/B) with the SP 9 and I have to tell you, although the REF 3 was/is better, it wasn't a jaw dropping difference.  and that retubed SP 9 MK II sounded really good.


WOW great re-tubing suggestion for the preamp that is not a match to the fully balanced amp!

It's all good, but to me it's OK to live few days with unbalanced depleted signal. ARC preamps have very high line-stage gain so the volume won't be deficient at all till the other unit arrives.

This does not see a good suggestion to me! In addition to depleated power output, many ARC amplifiers also make a lot more distortion when driven single-ended. If one is trying to evaluate the amplifier it won't be possible!

Since a short-term suggestion was asked for, so far the best solution has been Al's, to get a set of Jensen transformers (which will do and excellent job of single-ended to balanced conversion without editorial) to drive the amplifier. This will work quite well and is far less expensive than replacing the preamp! In addition, the preamp right now is a known value and will allow for a proper evaluation of the amplifier.

If found acceptable, then I would indeed explore the possibility of updating/upgrading to a preamp with a balanced design.