Due to constraints of a small 11 x 12 ft listening room and the difficulty accessing my turntable within a vertical rack, I've decided to place my turntable on a small table next to my listening chair. As this setup requires a 4 meter cable run between my turntable and full function preamplifier, I've decided to use a small stand alone phono preamplifier with 68db gain (MC) to sit next to my turntable. I am not terribly experienced with analog. Is it ok to use a 4 meter cable run between phono preamp and linestage? I'm sure it's better than sending an unamplified MC signal over 4 meters of cable to my full function preamplifier. Please note I do not have sufficient room to place my full function pre or my entire rack near the listening chair. Thanks for your opinions. Perhaps I'm overthinking this :))
Doing what you propose will often and perhaps usually be fine, but it depends on the output impedance of the phono preamp (the lower the better), the capacitance of the cable (the lower the better), and the characteristics of the shielding in the cable. Susceptibility of the phono preamp and the main preamp to ground loop issues (which is generally unpredictable), and whether the interconnection is balanced or unbalanced, can also sometimes be relevant factors.
Almarg is right Audiobrian, to get the best out of it we need to know the output impedance of your phono stage first.
Then I will calculate for you the maximum capacitance of 4mt interconect you should use, as it will roll off the highs a bit if not right, which Dkarmeli may be doing without even knowing it.
10-27-14: Paraneer I currently run 5 meters from a phono pre-amp to my integrated on a second table that I recently acquired. No worries! Paraneer (System | Threads | Answers | This Thread)
10-27-14: Mcgal I am running a 3m cable from my phono pre-amp to my pre-amp. I am using an upgraded cable for the 3m distance. Sounds great to me. Mcgal (Threads | Answers | This Thread)
Paraneer/Mcgal/Dkarmeli, I have no doubt that you guys are getting a nice sound.
But without doing the calculations in my last post, what I'm saying you may not know if your getting the very best out of it. And to do that I need the output impedance of Audiobrian's phono stage, then I can tell him what (pf) interconnect to use with that long run so he get's 100% quality transfer to his preamp.
But without doing the calculations in my last post, what I'm saying you may not know if your getting the very best out of it.
Well George, I am certainly all for getting the best sound I can get out of my system.
In my case, my second TT is a fully restored Technics SL-1500 with an Audio Technica AT-14sa. I was lucky enough to recently find a brand new, unused ATN14 Shibata stylus for the cartridge. Its just starting to break in now with about 50 hours on it.
I run the stock leads from the TT (I understand they are low capacitance and well suited for this table) to a Pro-ject Phono Box S pre-amp. Load setting are: Gain - 40 db Capacitance - 100 pf Impedance - 47K
Then I run a 5 meter Audioquest Golden Gate interconnect from the pre-amp into an unused line level input on my Marantz PM15S2 LE integrated. This rig gives me 95% of the sound quality as my main TT, a Pro-ject RM5.1 SE/Dynavector 10x5 combo using a 1/2 meter interconnect into the Marantz. Of course I don't expect it to sound better - its my secondary deck.
If you can suggest another cable I should consider, I am all ears. Thanks brother!
Al, I've got a similar situation going. I'm running a 15 to 20 foot SE run from my phono pre to my linestage. No ground loop or hum problems that I can detect.
The output specs of my ARC Phono Pre 8 are 200 ohms unbalanced; recommended load is 50K-100K ohms and 100pF.
And the input specs of my REF 5 SE are 120K ohms Balanced; 60K ohms SE.
Tom Tutay made custom SE I/Cs for me. I recall he said the I/C capacitance is 19 pF per foot. I guess it would be better if I could shorten the run to 5 or 6 feet. Oh well.
Assuming my I/C capacitance is about 400 pF, what impact would that have on the signal??
Bifwynne. Your output impedance of your AR P8 being 200ohm is fine to use 20ft of interconnect with, as even if the interconnect was 100pf per foot (=2000pf for 20ft) that equates to a -3db of 400khz which is bat hearing teritory.
Paraneer. For me to calculate yours with your 5mt of interconnect, I need to know the output impedance of the Pro-ject Phono Box S pre-amp, not the load impedance you've posted. Saying that, I've done a google on this Pro-ject and being solid state, I would guess it similar to Bifwynne above.
Tube output phono stages or preamps and passives would have the big ? on them, with these long interconnect runs.
Audiobrian the OP, needs to post what his phono stage output impedance is to see if he will get 100% sound quality transfer. But it looks like he's missing in action, even though he's the one who started this thread.
George, just an fyi, both of my ARC units are tube. But, aside from the electrical characteristics of the SE I/C, ARC gear is designed to be extremely synergistic with other ARC gear.
Btw, just inserted a DEQX Premate in between my ARC Ref 5 SE linestage and Ref 150 amp. Was a bit concerned about impedance compatibility, but all is well. Little nervous about inserting an artifact in the line signal too. But I think the DEQX benefits greatly outweigh whatever downsides there may be.
Kim and Al are very good mates of mine and operate just around the corner, putting Deqx premate in between anything will never cause damaging trouble even if there is a impedance mismatch.
Your Ref 5 has a 300 ohms SE ouput impedance, they (AR) recommend a minimum of 20k load, and I see no impedance mismatch with the Deqx 50kohm input impedance, and the output of the Deqx being SS should be fine looking at the 300kohm input impedance of the Ref 150.
Deqx don't give an output impedance on their website propaganda sheet, I must let them know to include it, I assume it to be around 50-100ohms.
Cheers George
PS: They (Deqx) just rang me and said the output impedance of the Premate is 600ohm XLR and 74ohm SE.
Bruce & Paraneer, I agree with George's comments. Also, Bruce, I see that ARC indicates for the PH8 a maximum load capacitance spec of 2000 pf, in addition to the "recommended load" spec of 100 pf.
George, thanks for the info on the DEQX. I'm planning to get one also, in a few months.
i have run up to 10 ft with no impacts that i could hear but i prefer to keep them close. Cable quality may be an issue (had that the first time i tried a long run) with RF or other interference but it can be done
George ... please remind me how you know about DEQX. There's been so many threads and posts, I forget who said what.
Take a look at some of my posts. I think the DEQX Premate has done a great job squeezing everything out of my Paradigm S8s (v3) that they can offer. The DEQXpert had a devil of a time aligning my S8s. He had to use my self powered subwoofer to do a lot of low end bass lifting because the tweeter/midrange drivers are wired in reverse polarity as compared to the onboard woofers. Time alignment is not perfect, but much better. The cross over between the sub and the onboard woofers is about 120 Hz. It's all about compromises.
Also, my room wreaked havoc on the FR. The DEQX mitigated a lot of room problems.
Overall, imaging, coherence and sonic hue is much improved.
Sorry Bifwynne, although I know Kim and Al from Deqx, I don't use their product, as I'm what you call a minimalist.
That is, all components in my quite large system are modded and impedance matched in such a way for me to get the signal to the speakers in the best possible way with the least amount of electronics in the signal path.
EG: if I could, the source with digital domain volume and very strong output stage a few watts, would drive a pair of 120db speakers direct in my fantasy world.
George -- I respect that. IME, using the DEQX came down to weighing sonic benefits against sonic costs. I gotta believe that inserting the DEQX into the signal path has cost something in the sonic sense. But, there are clear sonic benefits that outweigh those costs.
Time coherence mumbo jumbo aside, the room EQ correction alone is a major positive. I thought my finished basement/ sound room provided a great sonic environment for my rig. Nice plush sofa, a guest bed, carpets, plants and so forth.
WRONG!!
The DEQXpert carefully measured each speaker's FR at my listening position. The separate and combined FR plots were a mess, especially in the all-important bass and midrange spectrum. That alone caused major image smearing.
Of course, time aligning the drivers helped a lot too. Much more coherent imaging and less congested presentation.
I think many of our fellow hobbyists would be really surprised at just how sonically toxic their sound rooms may be. After all, the better speakers brands are probably voiced in an anechoic chamber. But that's not how the real world is.
The DEQX did some major signal twisting and bending to smooth out my speakers. They are NOT ruler flat ... nor perfectly time coherent. But they are "tamed" for lack of a better way to describe them.
So what's worse? Twisting and bending the signal being fed into my speakers, or letting one's sound room to bend and twist what comes out of the front end of the speakers by the time the sound reaches the listening position. Distortion is distortion.
Of course, the alternative is that one could turn their sound room into a sonically dead anechoic chamber and buy time coherent speakers that look like one eyed insects or Dr. Who Daleks.
Sorry for my extended absence....family concerns I'm afraid. Thanks to all who responded. I am using a Thor TA 3000 mk2 phono pre with output impedance of 300 ohms. It has 67 db MC gain, running 4 meters Cabledyne Silver Reference Unbalanced ICs into my VAC Ren Sig II linestage, driving VAC phi 300.1. I'm still considering placing my entire vertical rack to the right of my listening chair, allowing me to use the 4 meter run between linestage and amplifier as most do. Happy holidays!
I looked up the capacitance of your Cabledyne Silver Reference. The 4 mts of it will yield 160pf for each channel. This combined with the 300ohms output impedance of your phono pre will give you a -3db at 3.3ghz!! Which is no trouble at all, bats wouldn't even hear this hf roll off.
If you use the same interconnect between your VAC pre (which is half that of the of the phono pre at 143ohms) and your poweramp it is even better at -3db at 6.8ghz!!!
So the end result is you can use it either way, go with what sounds best and convenient to you, as either way you are not causing any roll off into the audio bands high frequency.
Thank you for your calculations and practical info George! I will now go with convenience, knowing there is no sonic price to pay either way:)) Much appreciated!
No problems Audiobrian, your 4mt long interconnects are so low in capacitance you could even use a 10kohm passive preamp with them no problems, this would be around -3db at 300khz still.
You must have a verified phone number and physical address in order to post in the Audiogon Forums. Please return to Audiogon.com and complete this step. If you have any questions please contact Support.
