mac said:
I failed to mention that my modules are early versions (like yours) and use the 15v zeners without the CRD.
When I called Digikey a few weeks back they had absolutely zero knowledge of this chip. As others have mentioned, if you want them now you have to be resourceful.
I`ll wait
The LM4562 may also be a nice opamp for my DEQX PDC which has a lot of OPA2134s in the signal path.Best regards
Gertjan
ghemink said:
I`ll wait
Best regards
Gertjan
Yes indeed!
I too have thought about modding my DEQX but have held off so far because it is such an expensive ($) piece of equipment....wouldn't want anything to go wrong....
Tempting though....
ghemink said:
Yes, I know, I do not want to screw it up either. However, I have the XLR output version. I could start with the opamps on the XLR board. If I screw it up for some reason I can just get a new XLR output board, a lot cheaper than a whole new PDC
Best regards
Gertjan
Ah...very nice!
I only have the standard RCA (unbalanced) version, which is all part of the main board I think.
The balanced option (DEQX) is another thing I have considered doing....having said that, I haven't experienced any ground loop/hum problems with it running unbalanced into the unbalanced inputs of my UCD monoblocs and Zap 2.3SE monoblocs (amps just running star ground config).
I am really looking forward to getting my hands on this new lovely looking opamp to see what it does to the UCD. I will hopefully be performing that mod (and a few others listed in this thread) over xmas when I get some free time.....
At the moment I am using the zaps as my amps. Compared to my somewhat standard UCD's, the zaps just sound more dynamic and alive....UCD's a little 'sterile' in comparison. The UCD's sure do have lower noise, but I still think the 'life' I get from the zaps is worth that tradeoff. (Lars was kind enough to send me the necessary smd resistors to convert the zaps into 'low noise' mode so I will try that over xmas too...then I can try both amps again to see which I prefer)
Cheers
whams said:
Ah...very nice!
I only have the standard RCA (unbalanced) version, which is all part of the main board I think.
The balanced option (DEQX) is another thing I have considered doing....having said that, I haven't experienced any ground loop/hum problems with it running unbalanced into the unbalanced inputs of my UCD monoblocs and Zap 2.3SE monoblocs (amps just running star ground config).
I am really looking forward to getting my hands on this new lovely looking opamp to see what it does to the UCD. I will hopefully be performing that mod (and a few others listed in this thread) over xmas when I get some free time.....
At the moment I am using the zaps as my amps. Compared to my somewhat standard UCD's, the zaps just sound more dynamic and alive....UCD's a little 'sterile' in comparison. The UCD's sure do have lower noise, but I still think the 'life' I get from the zaps is worth that tradeoff. (Lars was kind enough to send me the necessary smd resistors to convert the zaps into 'low noise' mode so I will try that over xmas too...then I can try both amps again to see which I prefer)
Cheers
If you want that more dynamic and alive sound I don't think you'll like the LM4562's, I find them neautral rather than have that upfront sound
t. said:
Thanks for that....it will be interesting to hear the opinions of this opamp as they come in.
I will still give it a go anyway...along with the other mods (in particular....removing the coupling caps altogether....all I did was change them to blackgate nx's), so it maybe the other mods that open up the UCD for me.
But yeah, I do prefer a dynamic sound (not necessarily 'upfront'), one which gets your feet tapping to the music rather then leaving you cold.
I'm going to be busy over xmas (again)...looking forward to it
Cheers
Like Whams, I find the UCD's a little laid back and would prefer a more dynamic 'live' presentation. If the LM4562 does not help with dynamics, can anyone suggest an opamp that would?
There is another interesting UCD hotrodding thread at the pink fish forum for those interested:
http://www.pinkfishmedia.net/forum/showthread.php?t=26205
Regards,
Dean
There is another interesting UCD hotrodding thread at the pink fish forum for those interested:
http://www.pinkfishmedia.net/forum/showthread.php?t=26205
Regards,
Dean
whams said:
Ah...very nice!
I only have the standard RCA (unbalanced) version, which is all part of the main board I think.
The balanced option (DEQX) is another thing I have considered doing....having said that, I haven't experienced any ground loop/hum problems with it running unbalanced into the unbalanced inputs of my UCD monoblocs and Zap 2.3SE monoblocs (amps just running star ground config).
I am really looking forward to getting my hands on this new lovely looking opamp to see what it does to the UCD. I will hopefully be performing that mod (and a few others listed in this thread) over xmas when I get some free time.....
At the moment I am using the zaps as my amps. Compared to my somewhat standard UCD's, the zaps just sound more dynamic and alive....UCD's a little 'sterile' in comparison. The UCD's sure do have lower noise, but I still think the 'life' I get from the zaps is worth that tradeoff. (Lars was kind enough to send me the necessary smd resistors to convert the zaps into 'low noise' mode so I will try that over xmas too...then I can try both amps again to see which I prefer)
Cheers
Yes, I went for balanced from the start. I wonder how much sense it makes to put an LM4562 on the UcD while still keeping all those opa2134 opamps in the DEQX? I also have a couple of UcD400 AD8620 amps that I plan to use for mid and tweeters (actually still using the NE5532 UcD180 for mid and tweeters) maybe should give those a try first before jumping to the LM. The AD8620 is far more expensive than the LM, would be said if it sounded worse :-(
Gertjan
ghemink said:
I have a similar situation. My Linkwitz Orion crossover uses 22 dual opamps.
The first component that I swapped opamps in was my DAC. I went from an OPA2134 to the AD8620 to the LM4562. I very much liked what I heard when I tried the LM4562 in it. My crossover was also using mostly AD8620s with a few OPA2134s and OPA627BPs (on adapters). Each time I replaced one of the opamps with the LM I could hear the difference. This is what finally lead me to try them in my UcDs.
If you have a component with a DIP socket maybe try replacing it first? If not, maybe it would be worthwhile cobbling together a little unity gain circuit on a protoboard so you can hear the effects prior to performing surgery on your PDC or amps.
Cheers,
mac.
mac said:
Hi Mac,
Thanks for the info. It sounds like even if you do not replace all opamps, you still could hear benefit, is that what you were saying?
I could try on UcD first (if I can get my hand on LM4562) and then later in the DEQX, however, starting with the DEQX may also be good (starting with the cheaper balanced XLR board). First clean up the source (DEQX) and finally the power amps sounds like a more correct approach to me. The DEQX main board would be more expensive of course, on that main board are the DACs and opamps that get to process the DAC signal, those opamps should be replaced as well for best effect of course, this would be a more dangerous (financially if I screw up) operation.
By the way, I guess the DEQX in combination with your Orion`s would be a good combination to try. Actually I build dipole speakers, different than orion but inspired by the orion, using different drivers though. The sound is great and with the DEQX it is a piece of cake to implement and change the filter frequencies and get everything phase linear as well (impossible, or at least very difficult, with conventional analog filtering).
Best regards
Gertjan
Daveis said:
A capacitance multiplier is basically what the name says. You have a certain relatively low value capacitance that is effectively multiplied in value by using an active circuit. Basically you have a normal bridge rectifier with normal sized filter cap first (say 4700uf), then comes the trick, you add an RC filter with a relatively large R, meaning in the order of a few hundred Ohm or even more, depending on what transistors you are using later on, and then you add a C, say 470uF�BThis RC filter forms a low pass filter that is used to drive the base of an emitter follower (if you know what that is). The collector of the emitter follower is connected to the main supply voltage (rectified and filtered with say the 4700uF cap), the emitter of that emitter follower is now the power rail voltage that goes to the UcD. You need still some capacitance, say 1000uF or so at that point, especially with Class D where you can have power supply pumping. Due to the low pass filter that drives the base of the emitter follower (usually using very high gain darlington transistors) the power supply ripple (100 or 120Hz ripple) at the emitter of that emitter follower is very strongly reduced. Using this method, you can get away with a much smaller capacitor after the bridge rectifier as the increased ripple would be filtered out by the active circuit.
Many people like enormous filter caps to stabilize the rails, however, keep in mind that with those big filter caps, very large and very short peak currents flow through the rectifiers, mains power lines etc, causing possibly other issues (EMI, RFI) with smaller caps, this is less as the caps will be charged during a longer period and with less high current peaks. And then using a capacitance multiplier, you can have both, ripple free power to the amps and lower peak currents drawn by the rectifier/filter cap.
Best regards
Gertjan
I tried something like this http://sound.westhost.com/project15.htm I didn't like the results with the amp but it worked ok with one of my pre-amps.
I also tried parallel caps in the amps psu, then snubbers etc now I just use T-network capacitors which sound the best IMO, no bypassing etc just the T-nets
I also tried parallel caps in the amps psu, then snubbers etc now I just use T-network capacitors which sound the best IMO, no bypassing etc just the T-nets
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