Class A Posted April 29, 2017 Share Posted April 29, 2017 My first post, so not sure whether I'm doing everything right as I'm a bit of a novice in this area (in regards to this forum as well as Audio in genera)! I have had a pair of Bowers&Wilkins PM1s from new for about four years and finally decided to get an amp and source worthy of driving them. I bought a Cambridge Audio 851A and CXN a few months ago (wish I'd read these forums a bit before making the purchase as I might've not gone with the 851A that looked so good on paper and in magazine reviews etc). I have bi-wired the speakers, with the amp's A and B outputs being used for LF and HF respectively. The CXN is set up to give fixed output level. My concern is the level I need to set the volume to before hearing a reasonable amount of sound. Anything below 25% is inaudible an it only starts getting loud at 75%. For an amp that's capable of 100 W per channel this does not seem to be right. Does anyone have any ideas. Things I've thought of myself include: Measuring the resistance (obviously can't measure impedance with a multimeter) of the speaker's LF and HF inputs to check they're matched to the amp's capabilities. Trying different sources to make sure it's not a low level output from the CXN (I've tried this with a DAB radio and don't believe this is the problem). Any thoughts much appreciated. Link to comment Share on other sites More sharing options...
aechmea Posted April 29, 2017 Share Posted April 29, 2017 Hi John, Welcome to Stereonet. The first task is to demonstrate that you are not a bot. That's done. Now you should be able to post in the forums, which seems to work for you. So, welcome. Some knowledgable people will be along soon to help you with your problem. Link to comment Share on other sites More sharing options...
Addicted to music Posted April 29, 2017 Share Posted April 29, 2017 John, This quote out of the review may help you: The Azur 851A's front panel is dominated by an attractive blue display with adjustable brightness. In addition to the tone controls, which can be switched out of the signal path, there are a headphone jack, seven source buttons nameable by the user, a smooth-as-a-kitten volume control, and a Mode button that lets the user shuttle between Volume, Balance, and Program modes. In Program, the gain can be trimmed for each source, which permits the user to bring all inputs up to the level of the highest gain source, or vice versa. What? No Mono button?Read more at http://www.stereophile.com/content/cambridge-azur-851a-integrated-amplifier#GBLhZ1owXmpEUzzm.99 http://www.stereophile.com/content/cambridge-azur-851a-integrated-amplifier#RJQm8BDpw7LwB3fj.97 See if you find it in the manual to ensure the levels are set correctly on all inputs 1 Link to comment Share on other sites More sharing options...
Class A Posted April 29, 2017 Author Share Posted April 29, 2017 Thanks very much. Sounds good I'll look into it. Link to comment Share on other sites More sharing options...
Weka Posted April 29, 2017 Share Posted April 29, 2017 Are you wired up via the balanced XLR or unbalanced RCA connections of both units? Are you getting full range sound at the speakers - disregarding the volume issue? Link to comment Share on other sites More sharing options...
Addicted to music Posted April 29, 2017 Share Posted April 29, 2017 Just remember there are several ways to skin a cat with volume control. If CA uses the digital method you will find that you end up winding the pot more towards its maximum volume. That's just normal for digital volume control as it reduces digital bit stripping to emliminate distortion. Link to comment Share on other sites More sharing options...
betty boop Posted April 29, 2017 Share Posted April 29, 2017 [moderator post] i've merged your threads and removed duplicates [end moderator post] Link to comment Share on other sites More sharing options...
Class A Posted April 30, 2017 Author Share Posted April 30, 2017 (edited) Thank you al for cleaning up my mess. Each time I entered the thread from my iPad it seemed to suggest I'd done it incorrectly. Anyway, believe I've got to the bottom of the issue. Amp specs state that when using both A and B outputs the speakers are to have a impedance of at least 16 ohm PM1 specs state impedance is 8 ohm Given that the speakers have a parallel crossover, removing the link means that I'm effectively trying to drive a set of woofers at 8 ohms with the A outputs and tweeters at 8 ohms with the B outputs Thus I've got loads that are not matched to the amp. There's a big difference between bi-amping which is probably worthwhile and bi-wiring that is probably not. My amp amp only really has two channels despite having two zones. By removing the link and using "zones" A and B all I'm effectively doing is moving the link from the back of the speakers to inside the amp. I think I should go back to wiring with a single pair for each speaker and re-connect the link. Please let me know if I've got anything massively wrong. John Edited April 30, 2017 by Class A Link to comment Share on other sites More sharing options...
Ancientflatulence Posted April 30, 2017 Share Posted April 30, 2017 I found the volume on the 840A the same ........using an 840C CD Player ......... I think it is just the way they are ............. I suggest PMing the fellow selling the one in the classifieds ..... see what he found .... http://www.stereo.net.au/forums/topic/122323-fs-cambridge-audio-azur-851a/ ..... Link to comment Share on other sites More sharing options...
Weka Posted April 30, 2017 Share Posted April 30, 2017 (edited) 6 hours ago, Class A said: Thank you al for cleaning up my mess. Each time I entered the thread from my iPad it seemed to suggest I'd done it incorrectly. Anyway, believe I've got to the bottom of the issue. Amp specs state that when using both A and B outputs the speakers are to have a impedance of at least 16 ohm PM1 specs state impedance is 8 ohm Given that the speakers have a parallel crossover, removing the link means that I'm effectively trying to drive a set of woofers at 8 ohms with the A outputs and tweeters at 8 ohms with the B outputs Thus I've got loads that are not matched to the amp. There's a big difference between bi-amping which is probably worthwhile and bi-wiring that is probably not. My amp amp only really has two channels despite having two zones. By removing the link and using "zones" A and B all I'm effectively doing is moving the link from the back of the speakers to inside the amp. I think I should go back to wiring with a single pair for each speaker and re-connect the link. Please let me know if I've got anything massively wrong. John Running 2 pairs of speakers requires 16 ohms (as per user manual), bi-wiring is the same load wise as having 1 pair of 8 ohm speakers connected. Suggest you need to check how the Input Gain Trim is set on the input you have the CXN plugged into. Edited April 30, 2017 by Weka Typo - CXN, not Oppo Link to comment Share on other sites More sharing options...
Class A Posted April 30, 2017 Author Share Posted April 30, 2017 Thanks Weka, Sorry I missed your earlier post. I'm using balanced (XLR) connections from a CXN. The CXN has its PreAmp (digital volume control) functionality turned off and the input gain trim is not being (all set to 0dB) used on the 851A at all as I only have one source. Because of this I'm pretty sure input trim is not a problem. However, you make some good points with respect to the speaker wiring and I'll consider this. Thanks again. Link to comment Share on other sites More sharing options...
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