MrLem

Wammer
  • Content Count

    196
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About MrLem

  • Rank
    Wammer
  • Birthday 01/01/1985

Personal Info

  • Location
    Cornwall

Wigwam Info

  • Turn Table
    SL1210
  • Tone Arm & Cartridge
    Ortofon Super OM20
  • SUT / Phono Stage
    Xone:23
  • Digital Source 1
    Leema Antila
  • Digital Source 2
    MiniDSP DDRC24
  • DAC
    Cambridge 840C
  • Integrated Amp
    Arcam Delta 60
  • Pre-Amp
    Bryston SP1.7
  • Power Amp/s
    MC2 MC450
  • My Speakers
    Tannoy SGM12x
  • Trade Status
    I am not in the Hi-Fi trade

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  1. A lot of my gear is rack-mount these days. What I'd really love to find is a proper full depth 19in rack which looks good in a living room, has at least partially open sides, and is not crazy money. Haven't done a lot of research. I probably should.
  2. The first half of The Hounds of Love (album) by Kate Bush is a curious one. It can sound great on the right system, but on most is a little dull and blurry. I used to think it was just a badly mastered album, but as I upgraded I found that it could sound wonderful. I'm not sure what causes the effect. I'm guessing either too much mid-bass for some systems to resolve or just straight-up tonal balance.
  3. Hello Mr F, hope you're doing well. Pleased to hear you have the remote sorted. If it goes again I think we have a solution. There's a checker for what the Logitechs can control. They're programmed by selecting from a list while having the remote connected to a PC by USB, so there's no need for codes. If it's on the list it'll work just from the product name. Your thingamy is on the list. You can check it here: https://support.myharmony.com/en-gb/compatibility Agree about wanting a nice remote. The Logitechs are fairly nice and would control my Bryston pre (second hand, no remote), but I bought a replacement from them anyway because it's gorgeous. Milled from a block of aluminium so doubles as a weapon if anyone tries to steal the system. Has light and motion sensors so it lights up if you grab it in a darkened room. Shiny. Dangerous if dropped on foot.
  4. Thanks for the pointers on finding further info. I agree tackleberry, I think that's about what it comes down to. ATCs are more accurate / capable, but the Tannoys sound 'nicer'. It's getting very tempting to keep them both, although it's an awful lot of money to double up on...
  5. I have a simple system: 1. Establish that I can afford the thing if I sell the thing it replaces. 2. Buy the thing. 3. Decide I cannot part with the thing it replaces. fin
  6. MrLem

    Any Experience?

    Ah well, if he's known to be ok then you're all good. Everything I can see on there looks really well done so should be fine. Can't see a spec sheet for that pre so no clue on the gain. Hopefully someone who knows their valves will see this and be able to give more insight. Based on the little I know though, I'm guessing that your pre has massive gain and a normal pre would resolve the issue. Attenuators might work as well, but you could even use the Mezmerize as a very high quality, bufferred attenuator, allowing you to stick with your existing pre. I've no clue on the impedance behaviour of valve systems so can't really comment on unbuffered attenuation.
  7. MrLem

    Any Experience?

    Yup. We'll pretty much have to take his word for it I think. If you want to ask more questions you could confirm that one of the two transistors mentioned has been used, but unless it's a scam they will have, and if it is he wouldn't tell you so there may not be too much point. The other thing you could ask for, which will be indicative of the transistors is the DC offset on each channel. End of the day though either he's kosher and so is the thing, or info from him is a bit pointless anyway. As for attenutation, 20db is a lot. I have a friend who services sound equipment and he had an Audio Research valve pre in the other day. He doesn't work with valves a lot and mentioned that the gain on it seemed insane. Given that it's a good make and seemed to be working to spec maybe that's a valve-pre thing. I'll ask him if he got to the bottom of it. Edit: He's tied up at the mo, but had a sec to tell me that valve pre-amps are often very high gain. If that's the cause, and it seems likely that it's at least a factor, then pretty much any non-valve pre should sort you out. Edit 2: If you can tell us the make and model of your existing valve pre I can see if I can find some data on it. We might be able to get to the bottom of this.
  8. Yeah, the guy I bought them from had them done. It seems to be a good job, but I have heard that replacing with a different kind can affect bass. It seems to be foam. That sound like an ok solution or should I consider having them re-done at some point? I'd also be grateful for any other info, especially a crossover schematic. I've found a link to one, but it seems use a dual-pole switch, which I'm guessing is not possible with the screws used in the SGM rather than the switches on the SRM so I'm not at all confident in it. I'll probably have the crossover refurbished at some point. I think (but am not sure) that it has electrolytic caps in, so am wondering about replacing with polypropylene or similar, but wonder if it'll change the character.
  9. MrLem

    Any Experience?

    That's true about gain. Most pre-amps have gain, which is to say that they will kick out a larger signal at max volume than they get in. These days that's almost never needed so you just lose a percentage of the volume control. This has a max output of the same as it's getting in so will give you a little more usable volume range, but if the issue is significant you might find that losing the ability to really finely adjust due to this build using stepped attenuators will offset that. I built mine with lightspeed attenuators and then switched to an Alps blue, due to... an accident. Stepped attenuator should be better but it might not be audible and you will lose the ability to make really fine adjustements. It's an easy part to swap out though, relatively. The Mezmerise is often called a buffer because that's what's at it's heart, but this version also has source switching and volume control, making it a full pre-amp. The signal path is source swicthing relays > volume pot > buffer transistors. The thinking behind the design is that attenuators screw up your impedance matching between source and amp (source wants to see high impedance, and amp wants to see low) so that's what the buffer does. Usually it's done by opamps or similar, but in this case it's just a pair of transistors and that is alleged to sound better in this implementation. It's certainly the case that opamps struggle with square waves while this doesn't. Real world audio doesn't have square waves, but it demonstrates ability nevertheless. Also the signal isn't going through an IC, for what it's worth. In short, the idea is to have a buffer for impedance matching but still keep the signal path as clean and simple as possible. The Salas part of the concept is feeding those transistors with very, very clean power. So, if you just need to attenuate, then a good solution is a buffer and attenuators. The former to sort impedance, and the latter to attenuate. But at that point you might as well make the attenuation resistors variable, and that is a pre-amp. Add the source switching and you have the Mezmerize. So yes, another solution would be to buy static attenuators and a buffer like the X10D. Another again, would be to just get attenuators and see if you can get away with the impedance.
  10. Blimey, is hard to precisely define such things. I guess much music gets a 'warm' sound from the upper bass. I'd guess the Tannoys have a bit of a frequency bump in that area, and possibly Q also enters into it, whatever that is...
  11. MrLem

    Any Experience?

    Yeah that is the problem. I don't think Pass sell the Mezmerize version, so to hear one you either have to build or find someone else who has. I'd offer to let you hear mine, but I'm in Cornwall...
  12. Y'know, I was keeping an eye on Lexicon listings too, but the Bryston was also on the list and came up super-cheap. Right, yes, photos. Right now the speakers are in front of a window so I'll not be able to get a decent pic, but here's a couple from the for sale listing I bought. I'll try to get my own after dark. The Bryston is off with the engineer for reconditioning, but I did manage to grab a blurry images before it went whilst attempting to photograph a CD player I'll be selling once lockdown restrictions allow. If anyone wants pics inside it, he's mailed me lots of them
  13. MrLem

    Any Experience?

    Hrm, based on the cost of parts and build time, sourcing, matching etc I'd say that's a pretty good deal. Based on how good it is that's an incredibly good deal. However, if you want it I'd snap it up. I don't know for sure but assume that Mr Pass and Salas put their designs in the public domain, provide boards etc based on it being for DIY only, not to sell on for profit, potentially in competition with them. So maybe it's fine, but it might not be and they might have it taken down if they find it. I don't recognise the PCB. I might be wrong but it's not a DIY Audio one, looks cheaper, and might be a Chinese knockoff. That's not a problem in itself, provided the circuit works and the correct parts have been put in it. Looks like a good job overall, although you'd have to get in there with a magnifying glass and a multimeter to be sure. Edit: You can see what the proper boards look like here: https://diyaudiostore.com/products/mezmerize-b1-buffer You can find the clone boards on ebay.
  14. MrLem

    Any Experience?

    Well, have a look at the BOM, and talk to Salas with any queries. He's a nice guy, really helpful, and tries to keep on top of part availability and the suchlike. I can tell you though that almost all the parts are easy to get, the only bit you have to watch is (from the BOM): "JFETS: (4pcs in signal path) 2SK170BL or LSK170B matched for IDSS" The 2SK part is the original. They stopped making them 20 or 30 years ago IIRC. When I last looked there were sources for genuine matched ones. The LSK is basically an attempt to clone it for the DIY hifi community. Last I checked they were producing them, but in small quantities due to yield issues. Be very wary or the last letter or two on the part. You can't use a different version. Also once you have the exact right part they need to be matched. That means either you buy a load of them and do your matching, which might get expensive and will need skills, or you do what I did and buy a matched set. Ask in the build thread for sources, I'm out of date. BTW I found the test graphs for mine. One is THD+N and the other frequency response linearity. Both tests at line level.
  15. MrLem

    Any Experience?

    Haven't used the B1 but have built and used a Mezmerize, which is the more advanced, DC coupled, source switching version with the Salas power regulation, and for which boards are available at DIY Audio. It's excellent, I can't really fault it. I also ran it through a mate's AP System One analyser and the performance was remarkable. Almost undetectable distortion, perfect square waves, linearity etc. I can't recommend the thing enough. Two things to bear in mind: This is a very accurate thingamy. Sometimes that's code for harsh, but not in case, it's just smooth and accurate, but I'd expect that to be a contrast to valves. Secondly, the transistors used have not been made in a long time so make sure you can get your hands on a matched set, of the right variant and spec, and genuine. There were sources when I built mine, and the last time I checked, but you don't want to buy all the rest of the bits then find you can't get em. I'll see if I can dig out my test data for the thing...