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Post by puffin on Feb 16, 2020 8:23:19 GMT
An interesting couple of days. These boards are are put together with spit and warm wind. You can mod them once if your lucky, going in for a second or third time is really chancing your arm. 4.7uf for the input gave too much bass, despite the caps being far superior to anything else I had. 2.2 ICW polyprops (dubious heritage having been in and out of other stuff) resulted in the signal dropping out (nothing to do with poor continuity on the board). Lastly some 2.2uf Wimas (275v) went in and bingo! sound very nice, although bass is still a little full. I have Tripath TA2024, 2020 amps 2 IRS2092 amps (one dual mono 50wpc, one stereo 125wpc and this sounds really good in comparison.
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Post by puffin on Feb 13, 2020 19:14:33 GMT
If you feel like brewing your own amps and tailoring the sound Class D is a very cheap way to "tune" your system. I have messed with Class D boards for over 10 years and had good and bad results. Just this week I have been re-boxing, and with a new PS a TPA3116 based amp said to be 50w into 4Ohms at 24vdc. When I first got the board I replaced the input caps for something more exotic and built a linear PS with some current smoothing trickery. It sounded ok, but I had so many other amps that I put it aside and it never really got used. I have now finished the re-case etc and plumbed it into the main system today. It now has an SMPS. It sounds more ballsy than I remember...in fact the bass is just too much...or have I been listening to amps with lean bass? I don't think so. The value of the input caps affect the low frequency response and what I put in a few years ago needs to be changed. Once I have done this it will be interesting to see if the bass is tamed.
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Post by puffin on Oct 13, 2019 16:19:52 GMT
Hi Paul, long time since I read this thread and I can see you have been on quite a journey since I visited you. Great to hear that you may now (finally?) have found audio nirvana. I must give that Yello track a listen. I seem to remember that Toy was very popular at the ASBO I attended. The Habanera - Yello is a good one too IMO. I had the vinyl album with this track on and it was one of the best recorded vinyl tracks I have ever heard. Hi Rob, Yes the system has moved on dramatically since you last heard it, I think I still had the Epos speakers back then? Yello are excellent, I particularly like Toy, Touch and The Eye albums. I will try out The Habanera too. You are more than welcome to pop over and hear how far the system has moved on if you are in the neighbourhood Paul. Sorry I missed your reply until now. If I am in the area would love to hear it. Yes, you had the Epos speakers then. Having seen the quality of the stuff you have nowit makes mine look like cast offs from Steptoe's yard
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Post by puffin on Oct 8, 2019 6:26:43 GMT
Hi Paul, long time since I read this thread and I can see you have been on quite a journey since I visited you. Great to hear that you may now (finally?) have found audio nirvana. I must give that Yello track a listen. I seem to remember that Toy was very popular at the ASBO I attended. The Habanera - Yello is a good one too IMO. I had the vinyl album with this track on and it was one of the best recorded vinyl tracks I have ever heard.
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Post by puffin on Mar 17, 2019 16:42:21 GMT
I am of course the author of my own gaffe. I should have headed this thread "Grounding Rod". In no way is this rod usurping or supplementing protective earth.
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Post by puffin on Mar 17, 2019 13:18:04 GMT
I bought a copper grounding rod years ago from what was then called RATA (Russ Andrews Turntable Accessories) which I never used as I was shit scared of banging it into the ground and bursting a pipe or hitting 240vac. Went to stay with my long term audio mate to attend the Tonbridge Audio Jumble and we were discussing these grounding boxes. What did he then produce......but his DIY version. Filled with several different kinds of magic stuff and other bits attached to a 4mm post. I will have to wait to hear from him as to what this does in his system, but I mentioned my copper rod and he said that they can be laid flat.....FLAT! I never knew that.
So over the next couple of days I dug a trench, lay the rod with 16mm2 earth cable and terminated with bits that allowed me to attach a standard RCA plugged interconnect (with signal core disconnected).
Then I wired it in to a spare socket and had a listen. I just wanted to listen to some choons and chillax, so I had no intention of adopting the "critical listening" mode.
I have read that those grounding boxes seem to tighten and deepen the bass (my mate told me that an earth rod works in the same way) and I think there may be something in that. A few weeks on and what I hear seems more relaxed, but no less detail and the bass is better.
Anyone else use one as a signal ground?
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Post by puffin on Nov 24, 2018 14:29:28 GMT
Brilliant, thanks Steve.
EDIT: All good, was set to Full Dynamic Range. I would have been surprised if my mate who is pernickety to the point of distraction had not done it.
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Post by puffin on Nov 24, 2018 10:11:50 GMT
I have been using a CA for about a year and have been very impressed for the £20 it cost me. I am not sure if it has been set to Dynamic cos my mate set it for me. In order to get into the menu shown above do I just connect to my laptop? Yes I am a greenhorn where this sort of stuff is concerned.
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Post by puffin on Nov 4, 2018 14:03:22 GMT
Then see my review of the SGS Grounding Box which is very reasonably priced and has had a startling effect on my system's sound quality. I had a look at that thread after reading about the RTZ. Is it just one connection IN and one OUT? Where do you connect it to? It looks like 2 4MM banana sockets?
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Post by puffin on Nov 4, 2018 13:59:42 GMT
ChrisB, what you say makes perfect sense to me. DSJR, an interesting read of your experiences with bridged amps. They are working for me.
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Post by puffin on Nov 4, 2018 13:54:12 GMT
My pair were said to be prototypes, although they were finished to a "finished" standard when I acquired them. They were faulty in that the bass planar panel was buzzing on one speaker. I only heard them at low volume and suspect that they were never played at what I would call a normal level. When I got them home I found that they were not only buzzing, but that both bass voice coils were rubbing due to the planar panel only being fixed at each corner. Over time this had moved causing the rubbing.
As the original design meant that there were voids L,R,Top,Bott I decided that I would use wedges to re-align the panel and correct the rubbing/buzzing. This took a long time to get right, when I thought I had cured it, and on another day and with different material the buzzing would come back to haunt me.
However, they have been playing well for about the past year. They were originally covered in a velour type material that was wrapped around the front and finished by stapling at the rear. The rear panel is a very heavy deadshete type material. This is removable. The tweeter was fitted over the "grille" so that this was the only driver showing. Removing the covers was a real PITA. They had used industrial strength staples which were almost impossible to remove.
Needless to say they look very home built and not pretty at all. All of the bare skeleton was hidden under a rather luxurious cloak. My dilemma is do I recover them and hope that my fix holds or leave them as they are looking awful, but sounding fine. I have made some makeshift removable grilles that make them look more acceptable, but not ideal.
There is very little info on the net about these. There is a US show report which has a picture of the range and the prices and that is about it. Pricing was a tad optimistic in my view. I am not sure which model I have as there were 2, one slightly smaller than the other. Mine are about 1 Metre high. They are in fact very heavy.
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Post by puffin on Nov 3, 2018 19:27:59 GMT
I am currently using EAR Primary Drive ope bakffle speakers, which are an unusual design, but I have grown to like them over the last year. I have some Lampizator open baffles that are gathering dust. I like some of what they do, but not all. They are a bit shouty to me (Saba Green Cone Tweets and Mids) I probably need to play with the crossover settings. Should I persist with these? They use the Eminence 15" bass drivers.
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Post by puffin on Nov 3, 2018 19:20:50 GMT
My first Dac was a QED Digit with one Positron PS. My first CD player was a Philips DC610 MkII which was not bad. Was the QED any better? or just different?....can't remember now. HIfi World used to have DIY supplements and there was one to convert it to use 2 Positron's one for the Analogue and one for Digital. So out came the soldering iron and the purchase of a second Positron. This sounded better than with just one PS. The build quality was not good and the last time I tried it it was not too well (hiss/crackle) on one channel. I must dig(it) it out and see what it sounds like.....maybe after some fettling.
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Post by puffin on Nov 3, 2018 19:10:16 GMT
Yes got it. I must say I am intrigued by what I have read of Mike's experiences with the RTZ grounding box. I would never discount anything until I had heard it. However the price is quite a lot out of my league.
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Post by puffin on Nov 3, 2018 18:38:53 GMT
Ah yes, I see what I you mean now. Are these the boxes designed by Wizards that contain ferrite dust or some other "dark" matter?
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Post by puffin on Nov 3, 2018 18:25:07 GMT
One of the POS terminals acts as a NEG, there is a push-pull as usual. In effect there is a NEG, is that what you mean?
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Post by puffin on Nov 3, 2018 17:35:13 GMT
As I understand it, bridging will almost double the voltage swing but will not increase the current capability. I'm happy to be corrected, we need colin14 to verify. The other key thing to remember is that the 'negative' speaker terminal is no longer at ground so don't try connecting grounding boxes and the like to them. Hi Martin, my speakers are connected to both POS terminals of both the L&R channels, the NEG chsnnels are not used.
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Post by puffin on Nov 3, 2018 9:48:37 GMT
2 P500s.
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Post by puffin on Nov 3, 2018 9:30:05 GMT
Has anyone gone from a two channel amp to a bridge mode? A lot of NAD amps have this facility built in. I modified a pair of Cambridge two channel amps some years ago to bridge mode as a project. I have recently been using them to good effect on the LF of my EAR Primary Drive speakers. There seems to be some divergence as to how much more power is available as a result of bridging, some say 4X into half the load, some disagree. What it does do is increase the current output and this seems to control things better. Of course it may not simply be that alone and a multitude of other factors come into play.
When I first posted (on another forum) that I was intending to modify the amps in this way I was told that the amps would self destruct as the heat sinking was far too flimsy to cope with the mod. Several years on they are still working and only run luke warm even when pushed pretty hard. It is a fairly simple mod and others might find an old amp or two you have laying around could be given a new/different lease of life.
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Post by puffin on Jul 1, 2018 12:29:57 GMT
Many years ago I made some Diy XLO style cables with the criss-crossed wires covering the core. They weren't bad for digital.
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