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Post by rob80b on Feb 25, 2013 13:00:00 GMT -5
Thanks Jackfish I was just going to give a few of them a call (if they're open Mondays).
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Post by garbulky on Feb 25, 2013 15:26:20 GMT -5
Interesting you said that. Since your bryston has that switch that's very NICE! My XDA-1 appeared to be harsh at higher or congested sounding with lots going on on my upa-2. But stuck in some 12 db attenuators and it reduced the problem. However, there is a slight loss of treble But I find the diff worth it with my current setup.. I wonderd what it wqas but suspected the voltage was too much for the 32db gain upa-2 amp. Now that you mentioned the sound changed when the switch was flipped, I'm leaning towards my original assummption being right... it's a problem with the voltage. A little annoying as you would think their gear should work well with each other....with a switch like the bryston being the ideal solution. I'm considering amps now with a low gain but wouldn't put the xpa-1 L out of the question yet!
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Post by brubacca on Feb 25, 2013 16:09:22 GMT -5
Let's just say that someone wanted to try a pair of attenuators in between a couple of components. how would one decide 3dB, 6dB or 12dB?
I'm guessing that too much attenuation would be bad.
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Post by garbulky on Feb 25, 2013 16:49:22 GMT -5
Brubaca, the only experience I had with too much attenuation was with my asus xonar essence st output to my headphone amp. Putting attenuators there made the sound quality poorer. However, an xda-1 out to my headphone amp required headphone attenuators. I feel that my current UPA-2's could do with a little bit more attenuation so I can explore the higher volume numbers on the xda-1.
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Post by AudioHTIT on Feb 25, 2013 17:22:54 GMT -5
Let's just say that someone wanted to try a pair of attenuators in between a couple of components. how would one decide 3dB, 6dB or 12dB? I'm guessing that too much attenuation would be bad. Along the lines of what garbulky's getting at is 'what problem are you trying to solve?' In his case he's trying to get up higher in the XDA-1's digital volume curve where it's less 'lossy', the goal would be to have 80 be the loudest you'd ever listen. In this case you would size the attenuator based on where your current loudest setting is. (I think he also has an issue with the input on his headphone amp.) However many with the USP-1 complain that the low volume curve is too sensitive, again the goal is to allow you to use more of the volume control so you have more 'steps' between soft and loud. While the two reasons are different it seems most find the 12 dB attenuators a good choice for these two examples, but the gain of your amp would also come into the decision. If an attenuator was 'perfect' the only downside to having 'too much' would be insufficient volume.
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Post by brubacca on Feb 25, 2013 17:33:48 GMT -5
A couple of you have talked about them so much that you have convinced me to try them. Kind of like after my free subscription to Maximum PC I thought I had to water cool my pc..
No seriously, I find a lot of my listening on my usp-1 and upa-200 to be around or below 9:00 on the dial, so I'd like to see how it sounds with the attenuators. Also want to try them with my Xda-1 directly to amp.
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Post by rob80b on Feb 25, 2013 17:46:31 GMT -5
Brubaca, the only experience I had with too much attenuation was with my asus xonar essence st output to my headphone amp. Putting attenuators there made the sound quality poorer. However, an xda-1 out to my headphone amp required headphone attenuators. I feel that my current UPA-2's could do with a little bit more attenuation so I can explore the higher volume numbers on the xda-1. With my UPA-2 I found it's built in volume worked just fine getting the output of the USP-1 tamed, it does go from zero to full 32db, I'm assuming you tried that first? Unfortunately or fortunately that was omitted from the XPA-200 so some attenuators are definitely needed if I'm to use it with the USP-1.
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Post by rob80b on Feb 25, 2013 18:45:17 GMT -5
Interesting you said that. Since your bryston has that switch that's very NICE! And while the voltage selector on the Bryston worked wonders, night and day I may say for some recordings, from what I've been reading some attenuators can and will change the "linear" input or output impedance causing odd anomalies with the sound. So I guess results will vary, but regardless, if the input stage of the amp can't handle the voltage from the pre that may be more detrimental than using an off the shelf attenuator. At this point it's difficult to ascertain what appears to be happening with the USP-1, is it the voltage from high level sources which causes a non-linear gain with the potentiometer and the volume control, other sources with lower outputs appear to fine so that there is a much better and wider linear progression from low to high volume. Now the question is, if employed, would the attenuators work better between the source and the pre, or the pre and the amp seeing that different impedance and voltages are at play. . it's a problem with the voltage. A little annoying as you would think their gear should work well with each other....with a switch like the bryston being the ideal solution. I'm considering amps now with a low gain but wouldn't put the xpa-1 L out of the question yet! It's fairly common, even those with a full Bryston system have experienced the exact same problem. Interesting reading www.uneeda-audio.com/pads/
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Post by garbulky on Feb 25, 2013 20:28:19 GMT -5
I suggest between source and pre but honestly it could even be at the amp ends
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Post by rob80b on Feb 25, 2013 22:40:51 GMT -5
Overall though, if you can tame the output and get the volume control between 10 and 1 o'clock for moderate to loud listening the USP-1 is an excellent preamp IMHO!
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Post by jackfish on Feb 26, 2013 16:39:47 GMT -5
I have my Rothwell attenuators plugged into a line input of my USP-1 which accept the analog signal from my Schiit Bifrost DAC (computer/USB and CD player/Coax are connected). The phono, tuner and tape are unattenuated as they need a little boost compared to the DAC.
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Post by rob80b on May 16, 2013 12:43:16 GMT -5
Just an update after acquiring some Harrison Labs 12db attenuators.
As I mentioned earlier on, I was able to tame the output of the USP-1 by choosing the 2 volt (23db, a reduction of 6dB) input sensitivity on the back of my Bryston 4BSST which really improved the overall sound by allowing the volume control to work on average between 10 and 1 o’clock as opposed 8 and 10 o’clock, especially with the Bryston BCD-1. The main benefits are, more room to work with the volume control, a lower noise floor and a more natural (smoother) signal at higher volumes with no loss of detail.
First I tried the attenuators at the amp end, using the 29dB/ 1 volt setting on the 4BSST; the volume control was now between 12 and 2 o’clock for CD playback, unfortunately12db attenuation was too much for vinyl playback as the potentiometer on the USP-1 could easily be maxed out and never really needed. So next I tried the attenuators (remember they are directional) at the “CD input” on the USP-1 to tame the BCD-1s higher than normal output. Preliminary listening results were excellent, even better than reducing the gain at the amp end. I noticed an even smoother top end; “the Flute Album” with Karen Jones was delight to listen with increased air and detail and over compressed pop music had room to breath at loud levels. If you’re using the USP-1 with a pre/pro, taming the source IMO is actually a better solution as it does not require recalibrating the sub and the other amps for HT, so a win- win situation. (that is, until the “free with purchase” placebo effects wear off ;D).
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Post by rob80b on May 16, 2013 13:03:33 GMT -5
(Anyone know where the Harrison Labs can be got in Canada, shipping cost from the states is around $25 from Parts-Express, can’t see why they can’t just be put in padded envelope with a few stamps.) BTW for those who are interested, the best price I found was direct from Harrison Labs, shipping was extremely reasonable with tracking to Canada!!!
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Post by Boomzilla on May 16, 2013 15:55:22 GMT -5
Parts-express has VERY inexpensive 3 and 6 decibel attenuators. I find 12 decibels to be just too much. Besides, if you wanted to, you could put a 3 dB on the input to the preamp and a 6dB on the output, or vice versa.
Either way, you get the volume pot up into the rising curve of the logarithmic gain. Using the dual attenuators, you also probably get less midrange compression than you would from a single 12 dB attenuator.
Just a thought...
Boomzilla
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Post by rob80b on May 16, 2013 16:20:37 GMT -5
Using the dual attenuators, you also probably get less midrange compression than you would from a single 12 dB attenuator. Just a thought... Boomzilla Hi Boomzilla You may be correct there, upon further listening there was something different in the over all presentation but I'll need to do some more comparisons to confirm.
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Post by garbulky on May 16, 2013 17:16:37 GMT -5
I've tried 24db, and it's way too much making the mids more pronounced. 12 db was the sweet spot for me.
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Post by rob80b on May 16, 2013 19:58:08 GMT -5
Using the dual attenuators, you also probably get less midrange compression than you would from a single 12 dB attenuator. Just a thought... Boomzilla Hi Boomzilla You may be correct there, upon further listening there was something different in the over all presentation but I'll need to do some more comparisons to confirm. Just needed a bit of re-calibration with the Velodyne SMS-1 for the sub, now I'm good to go, well, until I get the XSP-1 that is.
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Post by MV Guy on May 16, 2013 22:12:02 GMT -5
Hey Guys, I'm new to the brand, just bought an XPA-200 to replace my Parasound HCA-1500A and am looking forward to it's arrival mid next week. My plan is in the future to get a USP-1 to replace my B&K Pro 10 preamp. I think I'm following the logic from the OP regarding voltage and gain with respect to the position of the volume control. If one has an Emotiva preamp and amp, is this as big an issue? If not, is it then only the speaker sensitivity that comes into play?
My Imagine T's are also right about 90 DB sensitivity. I'm past the days of shaking the walls down, at times I like it full lets say, but I'm not playing music for my neighbors! Just curious about all this talk about attenuators and such. Cheers
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Post by Gary Cook on May 17, 2013 0:21:55 GMT -5
Hey Guys, I'm new to the brand, just bought an XPA-200 to replace my Parasound HCA-1500A and am looking forward to it's arrival mid next week. My plan is in the future to get a USP-1 to replace my B&K Pro 10 preamp. I think I'm following the logic from the OP regarding voltage and gain with respect to the position of the volume control. If one has an Emotiva preamp and amp, is this as big an issue? If not, is it then only the speaker sensitivity that comes into play? My Imagine T's are also right about 90 DB sensitivity. I'm past the days of shaking the walls down, at times I like it full lets say, but I'm not playing music for my neighbors! Just curious about all this talk about attenuators and such. Cheers Some people find the USP-1 and XPA-1/2/3/5 combos are a bit touchy on the remote ie; one push = large increase in volume. This is somewhat attributable to the high gain on those power amps which is 32 db. This is not the case with XPA-200 which has a gain of 29 db. Added to your 90 db speakers sensitivity (ie; not particularly high) I suspect that you may not need any attenuation. In my case I have a USP-1 together with an XPA-5 and I find it just about perfect for vinyl. With other sources (eg; using the DAC in the Bluray player for stereo CD's) it is a little touchy on the remote volume. But not so much that I have thought it necessary to fit attentuators. Cheers Gary
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Post by MV Guy on May 17, 2013 1:10:25 GMT -5
Thank you for the update Gary. It makes a bit more sense now. Now I just have to find a buyer for my B&K and I'll be in the market for that USP-1 Cheers Jim
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