• Content count

  • Joined

  • Last visited

Community Reputation

0 Neutral

About elac310

  1. UP (still looking for an endcap)
  2. UP (still looking for an endcap)
  3. Hi! I'm looking for an endcap for a studio reference I (or II); it's the shell that comes on the front plate left+right hand side (fixed with two lateral screws) to hide the mounting holes/mains screws. I need only one and these parts are not available anymore from Crown, I was told. Can someone help? Chris.
  4. Hi chris, Sorry about silence from me.....I had a fairly good xmas and new year, this week a close friend developed secondary cancer, so i have had my head up *beep* for the last few weeks. Sounds like you are about done with the amp, i have had several crowns with a mechanical buzz from transformers. just the way some of them are. No fan movement yet? All the best and sorry for delay replying chris karl Hi Karl, No, I still haven't seen the fan running until now in my home audio environment (30-40 sqm room). To get it started, I'm afraid I'd need to blow the roof off or get deaf.... Nearest neighbours are almost 100 meters away and they do hear my occasional tests (windows closed). The amp is not rack mounted; it stands freely on a special table, with rubber feet underneath so lots of air around etc. The speakers are 4ohms nominal (with minima at 3 ohms). Haven't managed yet to make some tests at a friend's place (he had no time over Xmas); he owns JBL 250TI which are much more difficult to move and he's a violent guy compared to me when it comes to the volume. Chris.
  5. Well, whatever it was... Many thanks to all for your views on this. To Carlos: I did not forget to put the switch in the 50Hz position when I did the 115 to 230 V conversion. Probably I don't need a fan anyway (LOL... I still did not manage to get the - new - fan running until now ...). And a very happy new year! Chris.
  6. Update: 1) haven't still seen the fan in operation yet despite turning occasionally the volume up to unreasonable levels in my home audio environment (but high sensitivity speakers) 2) haven't sorted out the slight mechanical transformer buzz (but no worries, I have the same on other amps of other brands); this being said, it seems that the power switch does not isolate the transformer totally from the wall supply (even at power off, the transformer can be heard); can someone confirm this? 3) have added decoupling caps on the power supply: 20uF MKP connected in parallel to the main 6800uF filterings caps and screwed diretly on the TO3-carrying plates; the sound seems a bit sweeter on the mid/high frequency band and perhaps slightly more detailed at low volume; I like this change. 4) this amp is definitly a bass freak: on Michael Buble's recent "Crazy Love" at high levels, certain tracks clearly show a significant imbalance and over-exacerbated low frequencies; the SR1 is not forgiving about that... the mix was apparently made for this recording to be listened to at low levels with some loudness effect. Chris.
  7. Thanks. Forget the story about the voltage conversion. The fan was dead when I got the amp sent to me (from 115V US). The other explanation is see is bearing/axis of the rotor have become worn out and because of the horizontal mounting of the fan and natural gravity, the plastic cover carrying the wings and the motor's rotating part would get in physical contact with the motor windings. Does it make sense?
  8. Power Base 2 Fan Replacement

    Have a look at fan manufacturer catalogues available online and identify your current fan's manufacturer and characteristics, especially voltage operation (AC or DC), air displacement capacity, dimensions (obviously) etc. Then find a direct replacement from the same or another manufacturer but rated with less dB if you can. If you're lucky you can find something. I would invest in a good fan, not necessarily the cheap computer plastic fan allegedly very silent. I found out that although some computer fan manufacturers pretend to have very silent fans, there is a physical limit below which it is difficult to go = if you need 100cubic feet of air per hour, you may not get anything quieter than 40-45dB even with brushless motors, specially designed propeller wings etc. The air flow-generated noise in itself can be significant (which may also depend on the air intake/exhaust diameter and everything else that would perturbate the most direct/straight airflow). Chris.
  9. Crown LPS2500 - Faulty Fan ?

    Hello Michael, In another post, I describe almost a similar experience but I detected the faulty fan immediately after I had bought the amp (second hand). In my case, the fan motor was fried (burnt). I've changed the fan for the best equivalent model I could find on the market, a Papst full metal fan (a Crown deserves the best...). I'm running tests now and in the next few days to make sure cooling is not an issue anymore. But still looking for an explanation why a fan would fry... Chris
  10. As indicated in the "amplifier general discussion" chapter, I'm now the happy owner of a Studio Reference I, bought second hand from the US and converted from 110 to 240V . When I did a quick check up, I discovered there was something wrong with the fan (NMB model 4715FS-12T-B50). It was rattling and partly blocking when I moved it by hand. I changed it immediately for what I believe was a better version from Papst (4606Z), with all identical electrical, mechanical and aerodynamic characteristics. The only difference is the blowing direction (the fan is just mounted the other way round now) and the full metal body and propeller. Out of curiosity, I had a closer look at the original fan and noted that the plastic plate on the back of the motor seemed to have slightly melted. I disassembled the fan and found out that the motor windings are totally fried (burnt) which had caused the plastic cover to heat and to get in touch with the windings hence the mechanical defect I noted first hand. Now I"m wondering what it could be that has caused the motor to overheat to that extent: 1) Electric surge in the mains supply (lightning)? the fan is 115VAC and thus connected on a primary winding of the transformer, hence its ability to work under 110 and 220V I presume. 2) bad set up and ventilation possibilities around the amplifier by the previous owner, leading the fan to work continuously and eventually to overheat ? The reason why I'm asking is to find out whether I should check other specific parts for possible defect/failure. The amp works fine at the moment and the new fan has had no opportunity yet to get into operation (home studio use). In any event, since the former fan was dead, I presume the amplifier's security would have activated the mute function in case of (over)heating, thus avoiding any damage to further parts. Does anyone have an explanation or similar experience with a fried fan? Chris.
  11. Karl "anyway how does it sound? perform? i would love to know! (we dont see many in uk) is the fan quiet?" Answer: OK; I got the circuit breaker and the new fan today and I built them right in this evening (no rubber damping on the fan, as announced, I just was too impatient). After I've blown the house fuses for the first floor equipment a couple of times (I had forgotten to change the position of another jumper for the 110 to 220V conversion in the amp although I was sure I had done everything right...), the amp has now been working for a couple of hours. Sound: very clean, powerful, good dynamics, no colouration nor harshness on female opera and jazz singers. Lots of small details; certain Jordi Savall recordings of medieval music were made in a church where one can her occasionally birds whistling and flying around in the upper part of the church; the resolution is good enough to identify the origin of this noise. Saturation and distorsion on Hugh Masekela's "Hope" is obvious. The bass is somehow surprising for me; the upper bass is very present but it does not hide the lowest octaves. The high energy of the upper bass gives indeed a great slam and exacerbated physical sensation. It can be too much sometimes (Paolo Conte "The Best Of" dig. remastered, East-West music, Diana Krall's "temptation" etc.). I've readjusted the speaker cross-overs to attenuate a bit further the four 15 inch woofers' roll off at 300 Hz and it's much better (in my own room environment and acoustics). In comparison, a Hafler 9505 sounds slightly more refined and a bit more cultivated in the bass but it goes very deep and low bass is articulated as well. The SR I exhibits in fact a personality similar to the Zeck A902 which is also initially a PA amp; it sounds very "direct". I"m really happy with this aquisition. The SR I performs very well. Although my Hafler 9505 and Zeck A902 are both rated at +500W /ch / 4ohms and the SRI has "just" twice that power, the SRI seems to have significantly more headroom (I've put the sensitivity switch in the 1,4V position on the SRI, so the comparison is quite fair I think). No sign of defect of any kind, dead silence in the speakers without source signal applied. The only strange thing is that the transformer buzzes very slightly even in power off position! It is obviously not entirely isolated from the house mains supply and perhaps the DC filtering on the primary needs a check (I vaguely remember having read there's something of that kind on this amp but I need to check shematics again). My valve output CD player goes directly to the SRI via a so-called passive preamp (in fact just a potentiometer and source in/source out connections). I was a bit concerned about source impedance matching since the potentiometer is 10K and the unbalanced input on the SRI is officially 5 or 10K (it's not fully clear to me yet). But I have nothing to complain about; sensitivity and bandwidth do not seem affected at all. Now to the fan...well, I can't say much. I haven't heard it until now, just as Crown say in the manual !! The amp is playing at more than comfortable room level (about 40sqm) and earlier in the evening I've turned the volume up to levels making my wife complain: no sign of fan to report (I checked for any possible airflow on two or three occasions). I'll challenge the fan tomorrow again, now the rest of the household is sleeping. Good night now. Chris.
  12. hi chris, good point, and to be honest im not sure if the srII has lower psu rails or even less outputs.....maybe i should go look before i shoot my mouth off.... maybe srII needs larger smoothing due to lower rail voltage and sloppy supplies as a result? anyway how does it sound? perform? i would love to know! (we dont see many in uk) is the fan quiet? all the best karl The SRI and II are quite seldom here too (France). In fact, I haven't switched on the amp yet since I'm still awaiting the 20A circuit breaker ordered from Crown to finalise the conversion to 230V (the version for 110V originally mounted in US versions is a 30A...). Just finding a reasonably good quality power plug with screw terminals that would accept 16A/2,5mm2 wiring turned out to be a nightmare. I don't get it how all this cheep platic crap produced in certain parts of the world manage to comply with European electric norms and standards.... I have also ordered a new fan (the ball bearings of the current one are cracky and the propeller tends to block in a certain position=risk of noise and failure). I was fortunate to find an excellent full-metal equivalent in the EBM-Papst catalogue (same size and ratings in every respect, including noise); I went through various manufacturers' catalogues to find a specially quiet one but to displace 160 liter of air per hour (100 cubic feet), it turned out impossible to get anything the same size rated at less than 45dB (most similar fans are in fact rated at 50 to 60dB). An engineer from Papst confirmed the physical constraints of air displacement. This being said, the air circulation was smartly conceived and the fan is located deep inside the amp; the case should thus attenuate the noise significantly, leaving aside air circulation noise through the vents. Perhaps I'll add some bits of rubber to the fan mounting to dampen possible vibrations further. As you may know, fan operation in the SR I is proportional to the heat produced and the manual claims that under reasonable levels, it should not start at all. The whole case of the amp seems to be designed as a heat dissipator for the output transistors. So that's about 60 pounds of convection cooling material. In any event, I have 103/105dB sensitivity speakers (more in practice due to stereo and room environment) so I don't expect to need much power / generate much fan noise for my usage, but we'll see what practice says. I'll keep you posted about this and how the amp performs overall (including, if you like, in comparison with a Hafler 9505, a Zeck 902A etc.). Cheers. Chris.
  13. Hello Karlos, I understand from what you write that you have great respect for the engineering design of others, especially crown equipment. Fair enough, I do share your views and I respect that myself. I do not intend to change anything unless necessary. What raised questions in my mind is the fact that the SR II, which is rated for half the maximum power of the SRI, has larger supply caps than the SRI (10,000 uF versus 6,800 uF). The SRI being able to produce 1200W per channel at 4ohms, the power supply needs theoretically to provide about 17A per channel/capacitor if my maths are correct. That's a lot for a 6800uF/160V cap. Chris.
  14. Im sure the crown designers knew exactly what they were doing when they designed the studio reference. So many audiophiles think bigger and bigger is better, why not just get the amp serviced cleaned and set up correctly and enjoy listening to it? Maybe you could waste some hard earned cash on a length of silver cable or some gold plated connectors! Hello Karlos, You misunderstood me; I'm not the silver "cable guy" (good copper is enough in my opinion). Besides, for your information: gold connectors are already provided on the SR I both on the Input PCB card and the input Jacks, and as regards the output loudspeaker binding posts! As you say yourself, Crown engineers know what they do. Don't they? But again, that's not my point. If you think I should stick to the original capacitor size, then explain why (e.g keeping existing time constants / loading time of the caps, the fact that the amp is class AB/B and needs less filtering than class A etc). Otherwise, if you have nothing meaningful to say and just want to make fun at the expense of others.... (you probably get my point) Chris.
  15. Thanks Stephane; yes, I know the sites you mentioned but I couldn't find an international sale on these in recent times. The funny thing is that this changed shortly after these posts, and there were at least 3 SRI available for international purchase; a good ear must have heard my call! I've now got one.