Interconnect turntable-preamp low capacitance

[Marek]

Hi.
Time ago I did number of RCA interconnects based on different cables for CD-Amp. Good experience that time.
Now I got an idea to build own phono cable as replacement of factory ProJect cables.

What I learned those cables have to be low capacitance 70-100 pF/m or less.

What is your experience here, what cables (on budget side of darkness please) works well - bulk cable. Termination will do locally.

Thanks in advance. Marek

[KariFS]

I have made some interconnects using standard RG174U cable. It is a bulk product, I bought mine at 1€ per metre. It is rated at 50ohm impedance and C is 103pF per metre, so quite close to what is considered ”ideal”. Remember, the capacitance is ”per metre”, so you can reduce that by reducing the length of the cable.

There are some drawbacks:
- ”Too cheap” => can it be any good
- The conductor is 7-strand copper clad steel (the shield is tinned copper) Some people prefer silver-clad copper, some want platinum etc. With these kind of current levels, the ohmic resistance is a non-issue, in my opinion.

This type of cable is made for radio frequencies (RF), it’s a no-nonsense industrial product. Not very exotic, and the ”hi-fi credibility” is not very high either. It works for me though. If you are careful when soldering the connectors, you can re-use them many times if you are not happy with the cable.

I have used this for a couple of 1m RCA interconnects from RIAA to amp and from DAC to amp. Not yet with phono level, as I have the cables soldered directly to te tonearm wires, but the next time I take the L75 apart, I will replace the cables with short RG174U.

Here are my DIY leads, covered in nylon mesh (also cheap, 0.5-2€ per metre).



The thick blue ”rubber cable” is the same type I currently have in my L75, the ends on this one are recycled from a pair of old Monster cables I made this one for comparison, but haven’t made any comparison tests yet. The other blue one is a digital coax cable, the RG174U seems to work fine for this purpose too.

[Marek]

I have made some interconnects using standard RG174U cable. It is a bulk product, I bought mine at 1€ per metre. It is rated at 50ohm impedance and C is 103pF per metre, so quite close to what is considered ”ideal”. Remember, the capacitance is ”per metre”, so you can reduce that by reducing the length of the cable.

There are some drawbacks:
- ”Too cheap” => can it be any good
- The conductor is 7-strand copper clad steel (the shield is tinned copper) Some people prefer silver-clad copper, some want platinum etc. With these kind of current levels, the ohmic resistance is a non-issue, in my opinion.

This type of cable is made for radio frequencies (RF), it’s a no-nonsense industrial product. Not very exotic, and the ”hi-fi credibility” is not very high either. It works for me though. If you are careful when soldering the connectors, you can re-use them many times if you are not happy with the cable.

I have used this for a couple of 1m RCA interconnects from RIAA to amp and from DAC to amp. Not yet with phono level, as I have the cables soldered directly to te tonearm wires, but the next time I take the L75 apart, I will replace the cables with short RG174U.

Here are my DIY leads, covered in nylon mesh (also cheap, 0.5-2€ per metre).



The thick blue ”rubber cable” is the same type I currently have in my L75, the ends on this one are recycled from a pair of old Monster cables I made this one for comparison, but haven’t made any comparison tests yet. The other blue one is a digital coax cable, the RG174U seems to work fine for this purpose too.

OK Thx. RG174U is a standard code so cable quality can vary from manufacturer to manufacturer. To be honest I tested and also made RCA cables based on different brands and do not see massive differences - more cosmetic  IMO. But as long as I am on low cost side I am happy and open for new-next.

[stratokaster83]

RG400 is also worth looking at, it's very similar to RG174 but with copper core instead of steel

[KariFS]

OK Thx. RG174U is a standard code so cable quality can vary from manufacturer to manufacturer. To be honest I tested and also made RCA cables based on different brands and do not see massive differences - more cosmetic  IMO. But as long as I am on low cost side I am happy and open for new-next.

Yes, it is a standard product, and the good part about that is that the capacitance rating is very tightly controlled, as is the impedance. Other than that, I guess there can be variations. Mine is manufactured by Tasker, a rather reputable European (Italy) manufacturer. To me the steel wire was a surprise, only noticed it after I had made the purchase, but thought that it is worth a try.

RG400 is also worth looking at, it's very similar to RG174 but with copper core instead of steel

Thanks for the tip, I may try to source some the next time I order stuff. My go-to vendor doesn’t seem to stock it. They have some RG cable with a copper core, but that is a single strand, probably better for internal wiring rather than interconnects.

[Marek]

Yes, it is a standard product, and the good part about that is that the capacitance rating is very tightly controlled, as is the impedance. Other than that, I guess there can be variations. Mine is manufactured by Tasker, a rather reputable European (Italy) manufacturer. To me the steel wire was a surprise, only noticed it after I had made the purchase, but thought that it is worth a try.

Thanks for the tip, I may try to source some the next time I order stuff. My go-to vendor doesn’t seem to stock it. They have some RG cable with a copper core, but that is a single strand, probably better for internal wiring rather than interconnects.

The main issue can be material of wire. Copper (and Silver) are taken as reference IACS for current transfer. Silver is slightly better but some opinions about amplified sibilants exist. Copper has IACS 100% (Silver 105) vs stell 7-15 so steel in general is "poor" conductor. But if it works why not.

[Marek]

Currently found Mogami 2964/2965. Cheap and low conductivity COAX cable 57 pF/m. Seems to be in required range of conductivity. Will post some remarks when I will finish it.

[be.audiophil]

What is your experience here, what cables (on budget side of darkness please) works well - bulk cable. Termination will do locally.

This depends always on MM cartridges inductance, its DC resistance and input capacity of your phonostage.

[Marek]

This subject gave me number of data worth to consider as quite interesting.

Cables - in general made of pure (or more pure, very pure, super pure OFC and so on) copper with IACS ca100-101 % so reference value in general.

PLUGS/SOCKETS - majority made of .................  BRAS or Cu alloys or even more exotic materials - in each case IACS below 100 or far away from 100% (brass 28%, gold 70-79%)

SO more important seems to be to look for pure copper connectors than whatever sophisticated cable.

From the other side Tin has IACS at 15% and is everywhere in electronics including signal(sound) path. So what to do.
Each element soldered to PCB has two "filters" on in-out legs made of tin.

Too much theory and philosophy but seems to be worth and logic to reduce number of weak-points on the road between source-speaker.

Never-ending game and a lot of fun doing something. Good to be on successful side of darkness.

My cables on the road - plugs, plugs, plugs. Have to invest to KLE copper to be correct against above.

[be.audiophil]

SO more important seems to be to look for pure copper connectors

Sorry but no

[Marek]

Sorry but no

No in general or No for KLE or .... ?

Just finished new interconnects for CD-Amp based on Mogami 2803 and KLEI Copper. Difficult cable to solder and prepare. Thin and quite inflexible, sensitive for manual mistakes.
But first impression quite interesting. Detailed sound, separated instruments, bright brasses. So far so good. Time to listen more and more.

First one on photo.

[be.audiophil]

No in general or No for KLE or .... ?

No in general.

Contact resistances, the connectors/plugs, their materials and cables are generally overrated. Most of what´s said in internet and publications is voodoo. What really matters is a form-fitting connection.

[Marek]

No in general.

Contact resistances, the connectors/plugs, their materials and cables are generally overrated. Most of what´s said in internet and publications is voodoo. What really matters is a form-fitting connection.

About voo-doo no doubts. Fully agree. Overpumped/overrated market with "superb" ideas/products. OK - Form Fitting connection - new challenge to understand and follow. More please.

[Adelmo]

No in general or No for KLE or .... ?

Just finished new interconnects for CD-Amp based on Mogami 2803 and KLEI Copper. Difficult cable to solder and prepare. Thin and quite inflexible, sensitive for manual mistakes.
But first impression quite interesting. Detailed sound, separated instruments, bright brasses. So far so good. Time to listen more and more.

First one on photo.

Hi,

I use sigle point RCA connector such as KLE with a 70 Cm long Mundorf wire made of Silver and 2% gold ( they said ) 0.5mm diameter to interconnect the Pre Phono and Integrated amp.

I am happy with this cables and connectors.

Rgds

Adelmo

[be.audiophil]

Form Fitting connection - new challenge to understand and follow. More please.

This is actually quite simple. The connectors must be tight and must not be able to slip off. Whether you use Klei, the older Bullet Plugs or their actual reproductions under the Star name, these will only fit firmly on the socket if it is long enough. Neutrik NYS 373 are simpler as well as cheaper and produce always a significantly better and stiffer connection to the socket.