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In Reply to: RE: Best Passive/Active Combination of Crossovers for IIIa's and T 1-D's posted by Satie on July 17, 2015 at 19:40:55
Satie, I wanted to thank you again and update you on the progress of this project. I received the DMC-1 and connected it as my TGP-5 was. It fired right up and works extremely well. It almost sounds better than the TGP-5. Perhaps it is newer and has fresher parts? Not sure on that one. In any case it is a duplicate in terms of remote and operation so it was a no brainer as far as programming-setup goes. Now I have to make some cables. I posted a link in my previous post in this thread, of the RCA plugs that I have. I have two sets. I also read in the reviews that these plugs are kind of thick and will not fit will on all units especially if the jacks are close. Do you have a preferred plug to use to make some cables, and what cable would you use that is reasonably priced? I know one can spend a fortune on cables but I am not that one. I was thinking about $20 or so for the plugs and matching quality cable. I spoke with the gentleman from Apex Jr.and he recommended 20 Gauge PTFE silver plated stranded copper, but it would be stiff. I have purchased wire from him before and it is excellent quality and very reasonably priced. I made some cables for my mids using his wire and they are excellent. It is one choice, and I am sure you have more. Please advise if possible.
Follow Ups:
I am a fan of the 20g SPC twinax cable
It is slightly to the bright side so fits well tonally with tube equipment.It is not my first choice for bass ICs but is tight.
I ground the shield only on one end and cut it off the other. I mark that end with the ground. In your grounding scheme that would be either at the source - if your sources are all grounded or at the preamp (which is what I usually do as it has its own ground so I can disregard what sources might not have a ground. In your case the TGP-5 is likely the better place to ground.
I like to use them with screw on locking RCAs or XLRs or light gauge DHL silver RCAs or knockoffs.
The Cardas Rhodium on Silver is the most I would spend on RCA connectors appx $50 per 4
http://www.partsconnexion.com/product7463.html
The Onix and Dayton (parts express) and Connex WBT knockoffs are good
On the really cheap side there are practical amphenol RCAs simple and sturdy no idea what they sound like but have minimal metal - which can be a plus.
These Neutric pros are nicely engineered and have a reputation for a darkish tone in case you need it. The twinax SPC is more white balanced and fills out the top octave more so than a neutral sounding cable. So this might be a better choice if your setup tends to sound bright or even white..
http://www.parts-express.com/neutrik-nf2c-b-2-profi-professional-rca-plug-pair--092-114
Blue Jeans cable make a digital 70 ohm cable with appropriate 70 ohm connectors that also serve as very good analog interconnects Particularly recommended for bass duties, where they are slightly tighter than the JPS superconductors
To get better bass from these SPC twinax use two runs and connect the ends of the lives of each pair and the neutrals of each pair and the shields of each pair. Do not connect the shields to the connectors, leave them to float.If you get hum then connect a drain wire to the shield at the end where your ground is (presumably the tgp 5) and attach it to the RCA neutral there or to the phono ground or body - whichever eliminates the hum..
In most connectors you will want a spacer made of a stiff but still flexible plastic - a dense foam PE or a polystyrene or PET would work. avoid vinyl.
Satie after careful consideration i have decided to go with the Parts Express Locking solder type connectors http://www.parts-express.com/parts-express-audiophile-locking-rca-connector-2-pair--091-1065 as I already own 4 of them, so cost is a factor and I think the quality is sufficient. The only complaint I have seen on these is a lack of instructions, and 8.3mm cable jacket requirements, but with the twinax I don't think that is a problem. Belden has one, if this is what you are referring to http://www.parts-express.com/belden-brilliance-8412-20-awg-2c-mic-line-instrument-cable-tinned-copper-braid-shield-per---102-1250 If you check the connectors out they have a "tang like" connector for the ground, so I assume that one would compress this on the shield? Perhaps you might offer some advice there. If these are not workable then I move to the Neutrik Profi or the screw type that you recommended, but that means the cost goes up. With the mods to the DCX I need to keep the cost down while seeking the best bang for the buck. I like the SPC twinax 20 AWG but I don't need the "bright side" as my setup tends to be on the bright side. I think something smack dab in the middle of the spectrum would suit me better as far as cabling goes. Have you ever used the Canare LT2S? http://www.canare.com/ProductItemDisplay.aspx?productItemID=57 This was highly recommended on The Home Theater Shack cable tutorial. Any further feedback would be greatly appreciated of course. You can also be assured that by the level of advice I have received here that i will do my best to participate in this forum and hopefully pass on some of what i have learned over the years by experimenting and talking with you guys. I love this place! :)
I have not used this Belden twinax but it seems ok. I suggest you read up a bit on what it sounds like since its inductance is on the high side. You need to know that the cable works for your single ended line level purposes.
No problem with using the PE locking RCAs. I use them too.
I did some more searching on this site of your previous posts concerning interconnet cable and found it on ebay.....20 AWG shielded twisted pair SPC... all parts and cable ordered thanks once again!
I thought you had Apex Jr lined up and its teflon mil spec SPC twinax was right in the field of vision on their site.in the 22 gauge at least.
I guess it is better you found the 20 gauge as it is more likely to be less bright.
Got the wire and the RCA plugs...looking forward to assembling some interconnects. You mentioned a spacer. I am not sure what you meant by that...do you have a link to one? In addition is there a way to terminate the cable end of the connector so that it looks neat and tapers to the wire...kind of like this.... but to the cable part of the RCA plug, so that it gives some strain relief and looks good.....https://www.parts-express.com/cable-pants-6mm-2-conductor-black-10-pcs--082-772
Thanks again!
First, don't get those.
The spacer is intended to address exactly this problem of a rather thin cable going into a connector designed for a coax. The solution is to use a spacer that will combine with the cable to create a shape like a coax so allow the set screw ( which does the strain relief ) on the connectors to get a good grip on the cable.
My favorite solution is 1/2 inch segments of the hard jacket peeled off of cheap RG something coaxial cable. Or alternately an appropriately sized cylinder shaped hard rubber (Poly propylene or polyethylene or like) to plug in the free space.
If you want to make it look nice then use heat shrink over the spacer and wire portion and back down to the cable before it enters the connector.. I don't do that since I like to keep the options on the designated use of the wire open.
I found a spacer material from some wall wart extender cables that almost appears to have been made for this wire. The inner diameter is perfect and so is the outer. I will post a step by step assembly procedure for these interconnects as I think it would be helpful, complete with pictures. I would like to add a "shiny/glossy" heat shrink tubing to the finished product for looks and to ID the cables better. A problem I am running into is finding a 3/8" or 9mm I.D glossy red and black heat shrink tubing that comes in a 3:1 ratio as that is what is needed to shrink to the approximately 1/8" O.D. of the 20 gauge wire. I have some non glossy that will work, but it is not near as pretty as the glossy. :) Any suggestions or links to a 3:1 glossy/shiny heat shrink tubing would be very helpful.
I never used a glossy heat shrink so can't help you sourcing it.
How about putting a layer of poly gloss lacquer on the plain heat shrink when you are done?
Satie..I have one question. As the signal path from the XLR and RCA outputs on TGP-5 is no different according to the manual, doesn't it make more sense to use the XLR outs for noise/hum cancellation. The manual states that they are both line level outputs and recommends of course, the use of XLR when possible. In this scenario, to refresh your memory, the TGP-5 outs are going directly to the amps. I am constructing the cables and I have purchased enough XLR connectors to get the job done using them. If I were to use RCA I would need to exchange the XLRs for RCA plugs. Of course I will do that if necessary.
Does the TGP 5 also have multichannel XLR inputs?
If it is indeed the same signal then you can use the XLR option.
Generally speaking I don't like using balanced connections with internally unbalanced gear because of the need for an extra active circuit or transformer to drive the balanced signal. If the amps are not internally balanced as well, then you have just added two stages to the signal path. So unless you have hum problems or have good reason to expect them or are running long cables then stick with single ended unless your devices are internally balanced.
The TGP-5 only has XLR outputs, no XLR inputs. Does that make a difference? The Crest amp uses only XLR connectors. The Rotel and PF-200 use RCA and the PF-200 actually uses phono as it is quite old and most likely a pro amp. I talked to the manufacturer and they said that it was originally quite an amp, priced in the $2500 range, and it is quite pleasant to listen to. Simon Ashton sent a diagram on how to connect an XLR to an RCA plug. Essentially # 1 and 3 to ground on the RCA plug. I will attach the photo, but you are probably familiar with it. From what I can glean from the manual the XLR and RCA outs are the same signal. The description is identical with the exception of recommending XLR for better hum cancellation. I will check the amp manuals to see which ones are or are not internally balanced.
For the bass amp I would not worry about excess active stages and just go with the XLR - I am assuming that would be the balanced only amp. Where the extra active stages make a difference is in the mid and tweeter amps and I understand those have RCA inputs. If so, then connect the mid and tweeter amps with RCAs not XLRs.
If your setup tends to hum much or have much RF, the balanced to RCA is probably not going to help you much with the grounds shorted together- if you need the hum issue addressed then get a balanced to unbalanced transformer to place physically near and before the amps (those are usually designed to work in either direction Bal to SE or SE to Bal). There is a variety of them available on pro audio web shops.
Guess I got confused..anyway the wire I purchased although more expensive is 20 ga. and if it is not as bright as 22 all the better. There is quite a price difference between 22 and 20 ga wire I noticed as well. Must be a lot more surface area.
Sorry I cannot find any 20 AWG SPC cable...must be missing something.
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