robmid Posted September 28, 2023 Posted September 28, 2023 I've found that the internal diameter of Jaycar RCAs can vary enough to sometime cause loose connections. Neutrik versions are available from Element14 for about $4.50 inc GST and they make perfect contact with the wobbles. Cheers, Rob
muon* Posted September 28, 2023 Posted September 28, 2023 (edited) I prefer low mass, so use KLEI's Classic sockets. Edited September 28, 2023 by muon* 2
robmid Posted September 28, 2023 Posted September 28, 2023 I found that 3 pairs of my KLEI Silver RCAs didn't last long after the small + contact stopped making reliable contact due to some serious cable swapping but the gold versions I now use, are still going strong, after two years of the same treatment and don't have the same weakness. The silver KLEI RCAs didn't seem to have a very tight grip on my Aurealis Dragon RCA's which allowed them them wobble, which surprised me. Rotating the whole socket so that pressure remained on the the + single point contact pin did help temporarily. A BIG PLUS for the KLEI sockets for me is that they can be removed from inside the chassis without having to unsolder any leads. The Neutriks sound a bit brighter than I like but have been reliable when I used them. Cheers, Rob
andyr Posted September 28, 2023 Posted September 28, 2023 On 28/09/2023 at 12:54 AM, mwhouston said: I’ve been buying the cheaper ones because the wrap overs don’t solder. But not a concern any more as the Rhodiums will be my RCA of choice from now on. They come in gold also, Expand Thanks for the comment about the 'wrap overs' - I went into Jaycar and was able to swap the 2x red sockets that I had bought last week (which had 'wrap over') for 2 sockets which didn't! (IE. they looked like the picture on their web-site.) I bagged the last 2 that were there ... so I think in their never-ceasing search for lower buy prices ... they may have changed suppliers and the pic on their web site is out of date? On 28/09/2023 at 2:25 AM, mwhouston said: Outside. Expand I've ordered a pack of the gold-plated CMC ones - and they've already been shipped. So I'll see how I like them, when they arrive. The only issue for me might be they seem to incorporate quite a bit of metal - like @muon*, I prefer low mass. Thanks for this, Rob. On 28/09/2023 at 3:41 AM, robmid said: I've found that the internal diameter of Jaycar RCAs can vary enough to sometime cause loose connections. Expand Yes, others have said that, too. On 28/09/2023 at 3:41 AM, robmid said: Neutrik versions are available from Element14 for about $4.50 inc GST and they make perfect contact with the wobbles. Cheers, Rob Expand I'll order some - just to see how they are. My issue is that up till now, I've been using Vampire RCA sockets - but they seemed to have stopped making them. So I no longer have a 'go to' RCA socket. 1
andyr Posted September 28, 2023 Posted September 28, 2023 On 28/09/2023 at 3:41 AM, robmid said: Neutrik versions are available from Element14 for about $4.50 inc GST and they make perfect contact with the wobbles. Cheers, Rob Expand Rob, I've searched on the Element14 site ... but have not been able to find the black ones. Do you know the part no? They also sell these: ... Multicomp Pro, rather than Neutrik; do you have any idea of their relative 'goodness'? 1
andyr Posted September 28, 2023 Posted September 28, 2023 On 28/09/2023 at 5:56 AM, robmid said: The Neutriks sound a bit brighter than I like but have been reliable when I used them. Expand Looking at the detailed info ... it seems the Neutrik RCA sockets are gold-plated brass ... whereas the Multicomp Pro ones - here: ... are gold-plated copper! So I will order some of these to check them out. (Just have to find out the part no. of the red ones! )
robmid Posted September 28, 2023 Posted September 28, 2023 On 28/09/2023 at 9:06 AM, andyr said: Looking at the detailed info ... it seems the Neutrik RCA sockets are gold-plated brass ... whereas the Multicomp Pro ones - here: ... are gold-plated copper! So I will order some of these to check them out. (Just have to find out the part no. of the red ones! ) Expand Mmm. They look the same and I didn't realise there were two manufacturers. I have a feeling I might have ordered a different colour from each one. Neutrik prices vary too??? NYS367-0. Neutrik Black NYS367-2 Neutrik Red NYS367-9 Neutrik White NYS367-4 Neutrik Yellow Cheers, Rob 1
mwhouston Posted September 28, 2023 Posted September 28, 2023 On 28/09/2023 at 11:58 AM, robmid said: Mmm. They look the same and I didn't realise there were two manufacturers. I have a feeling I might have ordered a different colour from each one. Neutrik prices vary too??? NYS367-0. Neutrik Black NYS367-2 Neutrik Red NYS367-9 Neutrik White NYS367-4 Neutrik Yellow Cheers, Rob Expand OMG, now what are you going to do?
robmid Posted September 28, 2023 Posted September 28, 2023 They are obviously catering for WAF with this colour range.
tuyen Posted September 30, 2023 Posted September 30, 2023 Found 4x Mundorf 0.1uf silver gold oil caps in spare parts bin so stuck them in as bypass on the coupling and decoupling caps on the chifi blue velvet tube preamp. A worthwhile mod/upgrade I can highly recommend. some background info on the chifi unit: https://www.blackdahlia.com/html/Tip_98.htm 4
mwhouston Posted October 1, 2023 Posted October 1, 2023 On 30/09/2023 at 3:36 PM, tuyen said: Found 4x Mundorf 0.1uf silver gold oil caps in spare parts bin so stuck them in as bypass on the coupling and decoupling caps on the chifi blue velvet tube preamp. A worthwhile mod/upgrade I can highly recommend. some background info on the chifi unit: https://www.blackdahlia.com/html/Tip_98.htm Expand I have read where bypassing high quality interstage caps is not a good idea. Reason is you can introduce time slurring as each component has it’s own unique time constant (propagation delay). Good caps should be fast with low memory issues. Bypassing means you now have two caps with different time constants with the lower capacity caps passing high frequencies slurred against lower frequencies from the larger cap. Cheaper interstage will benefit from a smaller quality bypasser. Big caps like 470uf Cks will benefit greatly from bypassing. For me I use 0.1uf polies. 2
aussievintage Posted October 1, 2023 Posted October 1, 2023 On 01/10/2023 at 12:18 AM, mwhouston said: I have read where bypassing high quality interstage caps is not a good idea. Reason is you can introduce time slurring as each component has it’s own unique time constant (propagation delay). Good caps should be fast with low memory issues. Bypassing means you now have two caps with different time constants with the lower capacity caps passing high frequencies slurred against lower frequencies from the larger cap. Expand If true, the same thing would happen when you bypass power supply and AF bypass caps as well. All of them are part of the signal path and have different time constants against the various impedances in the circuit. 1
mwhouston Posted October 1, 2023 Posted October 1, 2023 On 01/10/2023 at 1:07 AM, aussievintage said: If true, the same thing would happen when you bypass power supply and AF bypass caps as well. All of them are part of the signal path and have different time constants against the various impedances in the circuit. Expand I always bypass big PS caps. The reason here is different. Big PS caps are noisy and the bypass cap shorts that noise to ground. But often I also add 4uf Russian PIOs to, as you stated above, provide a clean easy path for the audio. I’d rather the audio return go through a PIO cap than large electro. Also the smaller PIO is quicker to recover in the case of short quick PS demands.
aussievintage Posted October 1, 2023 Posted October 1, 2023 On 01/10/2023 at 1:13 AM, mwhouston said: I always bypass big PS caps. The reason here is different. Big PS caps are noisy and the bypass cap shorts that noise to ground. But often I also add 4uf Russian PIOs to, as you stated above, provide a clean easy path for the audio. I’d rather the audio return go through a PIO cap than large electro. Also the smaller PIO is quicker to recover in the case of short quick PS demands. Expand Yes, the reason is different but but you still have the differing time constants you were saying were a bad thing. 2
mwhouston Posted October 1, 2023 Posted October 1, 2023 On 01/10/2023 at 1:15 AM, aussievintage said: Yes, the reason is different but but you still have the differing time constants you were saying were a bad thing. Expand Audio returning through a 40,000uf cap I cant see as a good Idea. Through a small PIO, personally, I see as better.
andyr Posted October 1, 2023 Posted October 1, 2023 On 01/10/2023 at 12:18 AM, mwhouston said: I have read where bypassing high quality interstage caps is not a good idea. Reason is you can introduce time slurring as each component has it’s own unique time constant (propagation delay). Good caps should be fast with low memory issues. Bypassing means you now have two caps with different time constants with the lower capacity caps passing high frequencies slurred against lower frequencies from the larger cap. Expand My understanding also, Mark. For the same reason, larger values of capacitors in an XO should be made up of several equal/nearly equal value, smaller caps - not a large one plus a small one. 1
aussievintage Posted October 1, 2023 Posted October 1, 2023 On 01/10/2023 at 1:18 AM, mwhouston said: Audio returning through a 40,000uf cap I cant see as a good Idea. Through a small PIO, personally, I see as better. Expand Still missing the point that, after you bypass it, it is going through both. You were worried about that situation with interstage caps, you should have the same worry about this, and as I also mentioned large AF bypass caps which I have also seen bypassed by smaller caps. 2
mwhouston Posted October 1, 2023 Posted October 1, 2023 On 01/10/2023 at 2:10 AM, aussievintage said: Still missing the point that, after you bypass it, it is going through both. You were worried about that situation with interstage caps, you should have the same worry about this, and as I also mentioned large AF bypass caps which I have also seen bypassed by smaller caps. Expand Get your point but bypassing in the two different situations for two different reasons.
tuyen Posted October 1, 2023 Posted October 1, 2023 I’ve read the same thing few times too. Have experimented over the years and honestly can’t say I really hear any obvious smearing. I certainly hear the sonic benefits of the ‘good’ bypass cap though. I would likely go just 1 ‘good’ cap instead of bypass if I have the choice though. But that’s more just to satisfy my ‘purist’ approach. 1
mwhouston Posted October 1, 2023 Posted October 1, 2023 On 01/10/2023 at 3:41 AM, tuyen said: I’ve read the same thing few times too. Have experimented over the years and honestly can’t say I really hear any obvious smearing. I certainly hear the sonic benefits of the ‘good’ bypass cap though. I would likely go just 1 ‘good’ cap instead of bypass if I have the choice though. But that’s more just to satisfy my ‘purist’ approach. Expand Nothing beats a good cap. Interstage or other. But you don’t have to spend a fortune. For me the better Mundorf EVO Oil caps or Supreme (in my EL3N amp recently completed) for interstage and their Audio grade 22,000uf electros for PSs - bypassed of course.
muon* Posted October 1, 2023 Posted October 1, 2023 (edited) I'll avoid bypasses when ever I can, my amp has Mundorf HV Electro caps (main filter caps) Solen PB (decoupling to the front valves) Andyn True Copper Max for inter-stage, none are bypassed. Edit: I bypassed some of the main filter caps in my modded Marantz CD60 and something went wrong a few months later with low use and now there are crazy negative voltages on the op amps, still have to dig in and find out why. Edited October 1, 2023 by muon* 2
mwhouston Posted October 6, 2023 Posted October 6, 2023 This enclosure and PS started as a F5 build but after trying two different F5 boards I gave up. Neither was quiet. With a 300VA tranni and 132,000uf of Mundorf Mlytic audio grade caps (bypassed by polies) it should have been dead quiet. I tried it with these LJM ClassAB 120W all bipolar modules and it worked very well. The original modules ended up in “Clarity” a 70W SS amp which got sold. Now some new modules added. Under test sounding very good. DC offset is servo controlled and sits around 1mV. The amp should produce a very clean 80W RMS. The modules are very low distortion types and run dead cold. 1
Jehuty Posted October 6, 2023 Posted October 6, 2023 Mark, have you ever considered using EI trannies instead of toroidal? That could potentially address the noise issue. 1
mwhouston Posted October 6, 2023 Posted October 6, 2023 On 06/10/2023 at 2:24 AM, Jehuty said: Mark, have you ever considered using EI trannies instead of toroidal? That could potentially address the noise issue. Expand I’ve built about F5 s using the same PS and never had a problem. But Im guessing its something to do with the enclosure. Im over it.
mwhouston Posted October 7, 2023 Posted October 7, 2023 (edited) I like to use a pair of Cunningham 71a tubes in my “MWH” preamp but noticed yesterday an imbalanced in channel volume. Swapping tubes around (L to R) the imbalance followed. Dropping in a pair of RCA showed two things, firstly the volume jumped up a good 3db and the balance perfect. But I like to keep the RCAs for my 1/3W “Intermezzo” amp. Fortunately I had one Cunningham remaining. All good now a balance in channels with good output. And I can drop the RCAs back into Intermezzo. But also two low output tubes. I don’t really want to purchase any more 71a tubes so hopefully what I have will last. I may still mod Intermezzo to work with both 71a and some blue 45s I have. One switch will do to swap filament voltages using diodes to drop 2.5V. http://retro-thermionic.blogspot.com/2020/04/mwh-1920s-ux-171a-tube-preamp.html http://retro-thermionic.blogspot.com/2013/03/intermezzo-1920-ux-171-power-amp.html Edited October 7, 2023 by mwhouston
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