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Looking to make RCA interconnects - Single or dual signal cable? Also wanting to make a phono cable too!

Chrispy

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I skimmed and scanned kabusa.com for wiring and found the tonearm section but that did not mention anything about special wire parameters. Perhaps it is time to get at it and just use the Canare wire you chose @MrOneEyedBoh
Yeah I didn't see much on the site for the 1500 particularly, was more curious if they had some specs/ideas for OP.
 

Doodski

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Yeah I didn't see much on the site for the 1500 particularly, was more curious if they had some specs/ideas for OP.
Me too. I was very curious. if all else fails purchasing a DIN to RCA phono cable and then chopping off the DIN plug and soldering on some RCA's would probably assure a phono cable match is done. I did that in the past and physically the cable appeared like any other quality coax cable used for RCA terminations in general although examining the cable's physical layout doesn't mean it is or isn't specially designed for phono use.
 
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MrOneEyedBoh

MrOneEyedBoh

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Me too. I was very curious. if all else fails purchasing a DIN to RCA phono cable and then chopping off the DIN plug and soldering on some RCA's would probably assure a phono cable match is done. I did that in the past and physically the cable appeared like any other quality coax cable used for RCA terminations in general although examining the cable's physical layout does mean it is or isn't specially designed for phono use.
Will look into this
 

dlaloum

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Typical period TT cables, including the tonearm, added up to around 100pf

The tonearm itself is usually around 20pf to 30pf, so you want to ensure that your interconnect is no more than 70pf

Keep in mind that the cartridge loading will be the interconnect + tonearm cabling + load within the phono stage.

So one of the difficulties with something like an AT95VM - is that many phono stages have 200pf onboard - 200PF at the phono stage +100PF tonearm+cable = 300PF - and you are miles outside the cartridge spec of 100pf to 200pf.

From experience with multiple AT designs, when they say 100pf to 200pf, what they actually mean is 100pf, but it will still sound acceptable at up to 200pf (!!)

Shure cartridges on the other hand would do well at 400pf+ - but if you want wide compatibility in your setup, try to get your cabling as low capacitance as possible - I have one of my TT's down to 60pf.
 
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MrOneEyedBoh

MrOneEyedBoh

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Typical period TT cables, including the tonearm, added up to around 100pf

The tonearm itself is usually around 20pf to 30pf, so you want to ensure that your interconnect is no more than 70pf

Keep in mind that the cartridge loading will be the interconnect + tonearm cabling + load within the phono stage.

So one of the difficulties with something like an AT95VM - is that many phono stages have 200pf onboard - 200PF at the phono stage +100PF tonearm+cable = 300PF - and you are miles outside the cartridge spec of 100pf to 200pf.

From experience with multiple AT designs, when they say 100pf to 200pf, what they actually mean is 100pf, but it will still sound acceptable at up to 200pf (!!)

Shure cartridges on the other hand would do well at 400pf+ - but if you want wide compatibility in your setup, try to get your cabling as low capacitance as possible - I have one of my TT's down to 60pf.
So it sounds like I'm already up sh*ts Creek with that AT lol right?
 

dlaloum

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So it sounds like I'm already up sh*ts Creek with that AT lol right?
Well getting the AT MM's optimised is always tricky with many phono stages that have onboard C loading... - you need a phono stage where you can remove the C loading, leaving nothing but the tonearm and cable.... (if you are attempting to achieve the manufacturers specified FR... with higher C loading you will get something different - which you may like or dislike...)

Messing with the R loading will also affect things, and where the cartridge might be optimal at 47k and 100pf - there may be other combinations that are very good - as I recall, with an AT440MLa I ended up with a higher capacitance, but lowering R loading to 27k.... (and you can easily lower R loading using loading plugs on your phono stage input....)

The manufacturers today "assume" a load of 47k for all high output cartridges... But as shown repeatedly with many different cartridges - the optimal loading is often something different. Hence my suggestion of a setup that allows variance from 100pf to 500pf for C and from 20k to 70k for Resistance.

At some point I should also share my Cartridge model spreadsheet - you can feed in your measured performance, delete from it the influence of loading (cartridge H, loading C & R) and then apply whatever C & R you want to get an estimate of what your frequency response might be if you used those settings. (you can even use solution seeker algorithms to try to find optimal solutions!)

It's not perfect - it doesn't cater for aspects such as eddy currents (minimised in laminated core designs) - or other non linearities...

But it's a pretty good way to take an existing cartridge, and relatively quickly work out what settings might achieve an optimal Frequency Response.

I usually aim for as flat as possible. - But if you have a preference for a rising, or falling top end (or whatever else) - you could aim for that too...

My process:
1) Measure the current setup Frequency response with current loading
2) feed the raw data into the spreadsheet
3) Deduct the EQ / Loading impact - take a look at the "raw" cartridge / cantilever response (it will show up things like cantilever resonances)
4) Use solution finder algorithms to try to find a modelled Frequency response profile with minimal +/- db between a specificed frequency range
you will get differing optimums for a narrower FR, than for a wider FR - if you aim for 20 to 20kHz you will get a different and looser optimal setting, than if you aim for 40 to 15khz.... and sacrifice the extremes in exchange for a more accurate critical zone... - find a couple of options...
5) Try out the couple of optimal settings the model suggested....
6) re-measure, and re-import to the spreadsheet.... - optional but it is nice to know how far off the model is... - but you will often find substantial improvements in Frequency response neutrality going through this process.

All of which naturally assumes your target is neutrality - but you could use the same process for any preferred target curve.
 

datrumole

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Thanks. So that would be moreso like a traditional RCA cable, where they are joined together
yeah, their jackets are connected, they are also quite a bit smaller compared to the other two mentioned (can61s/mog2964)

bonus to all of the ones mentioned in this thread (i've been to redco and have seen/touch/felt all these mentioned), suuuuper flexible jackets. the mediabridge rca's i have feel like they are encased in cement in comparison

at the run lengths we are likely talking about, the difference in impedance and capacitance are negligible between the larger cables and the w2528. MAYBE at like >20ft, ok, sure, the larger diameter cables would have a the advantage. but since these are short runs, i prefer the small cable, much easier to manage and deal with
 
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