Part Sourcing Assistance/Advice Thread

[Pars]

Dealing with aliexpress sellers...

I ordered a replacement DSL-710A DVD drive for my Resolution Audio Opus 21 CD player from an aliexpress seller. The pictures were of a new unit with the correct LT7.9 firmware and a 2005 date code. The item I received (after a month of waiting) was a used unit, 2002 date code, and LT7.3 firmware.

Original ad:  https://www.aliexpress.com/item/1005001399857825.html?spm=a2g0s.9042311.0.0.17444c4dXcOvvp

What I got is pictured below. It does work, and solves the problem I was having, at least for awhile. I filed a dispute, asking for $20 back. I don't know if this is a translation/language problem, but the seller kept insisting that the laser is new, so I guess in his mind this is a new unit?

Messages:

Seller:  里面激光头是全新的

The laser head inside is brand new

Me: New means the entire unit, not just the laser. More than the laser can and does go wrong with these. I have filed a dispute for a partial refund. I had also sent a message before I purchased regarding the firmware revision. As pictured, it was LT7.9. The unit you shipped is LT7.3. Also, as pictured, it was a 2005 build date. Item shipped is 2002.

Seller:  你好出了什么问题，不能改的，现在改了价格就收不到货

Hello, what's wrong with you? You can't change it. Now you can't receive the goods after changing the price.

Seller:  你好我把钱全退给你你给个好评吧！

Hello, I will return all the money to you, please give a good comment!

 

At any rate, it looks like I will be getting a refund and can keep what he shipped. Ordering another one from a different seller, this one having good feedback for this drive from this seller. I had paid for the unit, including upgraded shipping, and get a message from him saying that the price has changed, and I owe an additional $24. WTF? This is the current ad: https://www.aliexpress.com/item/32793959385.html?spm=a2g0s.9042311.0.0.2aa74c4dp0pBzd

 

I had paid $65 plus $32 for shipping.

This whole experience is souring me on dealing with aliexpress, but finding these drives here in the US is problematic. Jeff Kait with Resolution Audio will sell me one for $250, which I may wind up doing.

[bhjazz]

I have a pair of DH Labs Pro Studio interconnects.  Bought the parts back in...I dunno maybe 2012.  I have Neutrik NC4MXX XLR plugs.  Just realized the pins are gold plating over brass.  The cables are 7 meter since my rack o' gear is to my right and the amps are in between the speakers.  In short, I hate these cables.  The high end is dry and bland/rolled off.    Sometimes if I crank the system up to 11 I can forget their ills.  I think they truly like that much power because they sound a bit better.  Otherwise, at evening listening levels I still hate them.  But try to go find another set that long for under a grand.  I could get by with a 5 meter pair.  

By moving some gear very close to the amps and trying other cables (Cardas Golden Cross, for example) the system breathes again.  I can hear life and breath and reverb tails.  

I ran across a discussion about VH Audio where someone was using VH wire and Switchcraft plugs, then had changed to WBT silver (WBT-0152) and found that the cables finally woke up. 

Just wondering what the consensus might be for me to try a similar tack (spend the dollars for the WBT ends) or if should just quit trying to make these what they may never be. 

Thanks!

[n_maher]

I don't think you'll find anyone here advocating for spending north of a grand on interconnects.

I'm also confused because you say your current cables use 4-pin Neutrik XLRs, you mean 3-pin right?  But then suggest that you might consider replacing them with WBT ends - as far as I'm aware WBT doesn't make XLRs.  And 5-7 meter RCA cables might be a bad idea.

Before spending more, I'd recommend spending less on cables and seeing if it makes any difference.

[tkam]

Anyone have a TKD 4CP2500 10K they'd be willing to sell?

[dsavitsk]

2 hours ago, bhjazz said:

But try to go find another set that long for under a grand.

I found a pair for under $70. And if you can tell the difference between those and something over $1K, the James Randi Educational Foundation will pay you more than enough to buy those expensive cables.

[bhjazz]

Nate made me double-check WBT and he is right: no xlr.  Thanks for that.  Also I pasted in the wrong model number which should have been NC3FXX-B (and the M model) so I know how I threw him off.  Sorry!

To me it's not amazing claims I need to accept, but my own ears.  No ghosts in my system.  😉

[n_maher]

@bhjazz - normally I'd say buy some good quality mic cable and fancy XLRs if you want and make your own, proper length cables. But:

8 hours ago, dsavitsk said:

I found a pair for under $70. 

With shipping on the parts from Markertek you'd struggle to spend much less than these folks will build you a set for.  

[mwl168]

In my own own humble experience with tons of different interconnects, ranging from my own DIY Mogami/Neutrik cables costing less than $50 to those boutique cables costing over $1K, it's usually a combination of the following factors if an interconnect cable does make  a difference:

1. the cable has quality/construction issues that induce capacitance, impedance or even connection issues

2. one or both of the equipments being connected have inadequate output/input impedance, drive capability, grounding, etc. 

3. length of cable, Nate already touched on this 

4. shielding of cable - especially in "noisy" environment 

Personally, I want my interconnects to be just that, an interconnects, and not injecting other artifacts. A properly constructed interconnect does just that and no reason for it to have a sticker price that resembles fine jewelry.    

 

Edited January 18, 2021 by mwl168

[bhjazz]

33 minutes ago, mwl168 said:

sticker price that resembles fine jewelry.    

I'm not advocating overpriced cables.  I've read the audio mags reasoning for Tara Labs and some others and wonder how materials and magic secret build techniques can make something cost so much.  On the other hand I have lots of inexpensive cables here and for many reasons, they have little synergy with my system.  But I've used this pair of cables in two completely different systems and both times they sound very bland.  Something isn't right. 

 

40 minutes ago, mwl168 said:

1. the cable has quality/construction issues that induce capacitance, impedance or even connection issues

3. length of cable, Nate already touched on this 

Since I never sleep on Sunday nights, this very thing went through my head.  I don't think it's the cable length because I have a 1M pair of these and they sound the same.  Still, I do wonder if their construction was wrong or if the grounds are wrong or...  I think I'll go dig through the Rane site and compare to what I've done.  

[n_maher]

There are only a few things construction-wise that I can think of that could go wrong and impact sound:

1. Cables wired out of phase.  I'd ohm out each of the pins to make sure this isn't the case and make sure you don't somehow have a crossed wire (literally) or a bridged joint.

2. Seriously poor joint on one (or more) of the connections.  Same as #1, measure the resistance from one end to the other. They all should be near zero  between matching pins and infinite between separate pins. 

3. Unshielded, which might allow for the introduction of noise but I can't see how this would affect frequency response. 

 

[bhjazz]

Yeah, something is toast.  I'll give those tests a try.  Thanks, Nate!

[mwl168]

I have one possible theory to consider;

Everything being equal, cable capacitance is in direct proportion to the length of the cable because of the amount of conductor material needed. Enough capacitance and high output impedance can form a low pass filter that, in extreme cases, can roll off the highs.   

 

[luvdunhill]

Hm; no idea - I use DH Labs cables and they don’t seem to “sound”, so perhaps that means they are “neutral”?

[bhjazz]

Neutral, LOL.  Reminds me of a cartoon in some audio mag back in the day.  Guy buying speakers and salesman says, "And as a special feature, when you reach age 70 we send out a serviceman to remove the tweeters."  

It does almost seem this cable pair is out of phase, though.  Interesting comment, Nate.  Gonna think about that some more.

Anyway, did Nate's tests last night, found nothing out of place.  Joints good, no crossed wires.  They look good.  The only thing I noticed was that the shield was connected to the plug on the source ends.  I don't think I really need that but read up a bit and world seems divided as far as do or do not do it.  Since these are not actual microphones I suppose I don't need it.  

Edited January 19, 2021 by bhjazz

[bhjazz]

On 1/18/2021 at 6:37 PM, luvdunhill said:

Hm; no idea - I use DH Labs cables and they don’t seem to “sound”, so perhaps that means they are “neutral”?

I agree.  And  am thinking this neutrality is part of my issue.  Adding neutral cables to an already neutral system can sometimes mean losing some system synergy.  When I moved into my house my audio room was just the speakers, the rack o' gear, records and CDs piled up and a wood kitchen chair.  Since then I've added tube traps, 2-person loveseat audio receiving couch, blinds, storage racks, etc.  So lots of things to soak up audio and maybe not enough to keep nice clean highs.  This might be my real problem.  

Incidentally, I was looking at how I had set up my Pass ACA monoblocks and realized that I had left the switch in a different position than maybe was intended.  I put it back to the balanced mono setting for XLR and was able to gain a little focus.  It may sound better now but am trying to ignore the self-inflicted placebo.  Time will tell.  

Edited January 21, 2021 by bhjazz

[JoaMat]

On 1/18/2021 at 4:52 AM, dsavitsk said:

I found a pair for under $70.

Did some “google” and found a supplier in EU of Mogami W2534 with connectors. Advice most appreciated.

[Pars]

Anyone have any idea what this damping material is? It is what was used by GNSC for their mods to my Resolution Audio Opus 21. It kinda looks like dynamat and is 3.4mm thick but doesn't feel like dynamat (or smell asphalt like). Is it Paxmate?

 

[bhjazz]

On 1/18/2021 at 2:42 PM, mwl168 said:

Everything being equal, cable capacitance is in direct proportion to the length of the cable because of the amount of conductor material needed. Enough capacitance and high output impedance can form a low pass filter that, in extreme cases, can roll off the highs.   

Winner.  

Got some time to compare the 7 meter version to a 1 meter version of the same cable this weekend.  No contest.  Low pass filter very much in effect with the longer cable.  Even did the maths calculationses on them.  With the shorter cable the music breathes better and that extra blanket was removed from my speakers.  To make sure I wasn't fooling myself, my wife (the one without the compromised hearing) was brought in to listen while I swapped cables back and forth.  While she doesn't speak fluent audiogeek she was able to describe what she was hearing and confirmed (without me leading the witness) that the shorter cables were less obtrusive. 

I later traded the Cardas Neutral Reference speaker cables for some older Audioquest F18.  That worked a treat as well although they are not perfect in the bass response.    

I think my real lesson here is combining too many neutral components may net a final system with a less natural final presentation.  YMMV.

[n_maher]

^^^ I feel like the most relevant discussion that this thread needs is confirmation that one of your wives has compromised hearing.

[Pars]

Barrier strips: For the carbon I'm building, I have 4 pairs of primary wires (2 transformers). I was thinking about using some barrier strip(s) to combine the primary wiring to the IEC (for the time being). Any particular ones any of you use and like for this type of application? Covered might be nice as well, since it will have live AC on it. I was looking at some at Mouser, but there is considerable choice, so thought I'd ask.

Edited February 6, 2021 by Pars

[luvdunhill]

36 minutes ago, Pars said:

Barrier strips: For the carbon I'm building, I have 4 pairs of primary wires (2 transformers). I was thinking about using some barrier strip(s) to combine the primary wiring to the IEC (for the time being). Any particular ones any of you use and like for this type of application? Covered might be nice as well, since it will have live AC on it. I was looking at some at Mouser, but there is considerable choice, so thought I'd ask.

I have used Cinch brand in the past. I like the solderable tabs as well.

[Kerry]

I'm looking for an HE90 jack.  PM me if you have one to spare or know where I can order relatively quickly.  I've been in touch with the manufacture, but it's going a bit slowly.

Thanks

 

[tee]

https://www.moon-audio.com/sennheiser-headphone-chassis-mount-connector-he90.html

[Kerry]

Thanks 👍

[jamesmking]

quick heads up KSA1220AYS transistors are now END OF LIFE 

https://www.mouser.co.uk/ProductDetail/ON-Semiconductor-Fairchild/KSA1220AYS/?qs=ljbEvF4DwOOJTVoo5AYsWQ%3D%3D

😞

mouser is currently out of stock

radio spares has stock

farnell is out

digikey is out

 

Edited February 26, 2021 by jamesmking