BMU Loan

Alfi
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Re: BMU Loan

Unread post by Alfi » Wed Feb 21, 2018 5:40 pm

BMU assessment just completed by me, with my thoughts are in the review section.

It’s all packed up now and booked in ready for collection by UPS tomorrow for sending to Cycle Coach who should receive it on Friday.

Thanks for the opportunity Doc.

Alfi.
Heavily modified LP12, Sole VIII sub-chassis, "In Sole" advanced polymer suspension, Ai bearing, PU7, DV20X2, Norton Airpower clone. Technics SL110A, AT 1005, Denon DL301A. NVA Phono 2 MC (2 power supplies), NVA P50 SA, NVA A40 Mk1 power amps, custom birch ply Allison 6/NVA Cube 1 clones, NVA TIS mk2 , SSC, LS6.

Lupus-Dei

Re: BMU Loan

Unread post by Lupus-Dei » Wed Feb 21, 2018 6:36 pm

Just read through your review alfi, would you consider the BMU might be slightly attenuating and rounding off the very upper frequencies on some of your recordings ?

Andy-831
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Re: BMU Loan

Unread post by Andy-831 » Wed Feb 21, 2018 7:18 pm

Alfi

Whats the Voltage coming out of the wall, could this be the cause of the humming (ie; if it's 230+10% )

Doc built my BMU with a slight step down, the valves in my 220v rated amp are now glowing nowhere near a brightly as when they were being fed 244v

Andy
Analogue
301 / 3012 / 2m black
401 / PU7 / AT33ev / Highphonics SUT
Phono 2 + extra PSU
Digital
Vortexbox, SBT / Teac Dac
Cambridge CXC
Amps
Glasshouse TVC, P50 Sa or Quad 34/44
Quad 303; 606 or Bel Canto Set 40 or NG 300B Set Monoblocks
Speakers
Tannoy GRF Memory.
Q Acoustic 3020.

_D_S_J_R_
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Re: BMU Loan

Unread post by _D_S_J_R_ » Wed Feb 21, 2018 7:25 pm

Sorry to butt in, but mine doesn't cut high frequencies down at all. If the recording is toppy (and with my ears currently recovered), you know it in no uncertain terms. It's just that added mains 'hash' is significantly reduced if not eliminated and the result through the speakers or headphones is a general lessening of 'mess' in the music that I find audible without it (the mess) being there. I was lucky enough to attend some gigs with jazz-drummer Alan Ganley years ago playing a simple kit using brushes most of the time. To hear how he could all but play tunes by gently caressing two cymbals with his brushed sticks was enchanting compared to the hard crashing favoured by other jazz drummers (Martin Drew for example). It's this kind of 'musical' subtlety that is enhanced when the stereo system gets better and it's something so many 'HiFi's' just don't do at all well...

If the speakers boom a bit in the bass and have a hashy rough top on their own, I suspect the positive effect of balanced mains may not be so audible as the speaker will be adding so much of its own, but if the speakers/headphones have half a chance of some sort of quality (and I do appreciate much of this is subjective), then you may find the benefits a BMU brings *to the music* to be well worthwhile and worth the outlay... Oh - and this difference transcends any tweaky add-ons you care to try, as it's more fundamental than that and I believe with good reason...

Alfi
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Re: BMU Loan

Unread post by Alfi » Wed Feb 21, 2018 7:46 pm

Lupus-Dei wrote:
Wed Feb 21, 2018 6:36 pm
Just read through your review alfi, would you consider the BMU might be slightly attenuating and rounding off the very upper frequencies on some of your recordings ?
Think not, rather grain has reduced dramatically.

Andy-831 wrote:
Wed Feb 21, 2018 7:18 pm
Alfi

Whats the Voltage coming out of the wall, could this be the cause of the humming (ie; if it's 230+10% )

Doc built my BMU with a slight step down, the valves in my 220v rated amp are now glowing nowhere near a brightly as when they were being fed 244v

Andy
Right now it's 242. See it sometimes high as 244. Never seen it below 240V here.

Alfi.
Heavily modified LP12, Sole VIII sub-chassis, "In Sole" advanced polymer suspension, Ai bearing, PU7, DV20X2, Norton Airpower clone. Technics SL110A, AT 1005, Denon DL301A. NVA Phono 2 MC (2 power supplies), NVA P50 SA, NVA A40 Mk1 power amps, custom birch ply Allison 6/NVA Cube 1 clones, NVA TIS mk2 , SSC, LS6.

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Dr Bunsen Honeydew
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Re: BMU Loan

Unread post by Dr Bunsen Honeydew » Wed Feb 21, 2018 7:56 pm

You need another solution, you must have something really odd during the day. Sometimes farmer are the very worst and putting pollutants everywhere including Elec. Some of the machinery make and mend is hilarious. So don't think living in the country is better, it can be worse.

I sounds to me your line impedance is so bad it is blocking what BMU can do. The only way to improve that in the past was get your own generator. Now you can just add some generation. In your case wind would seem best, and some batteries, between them you will lower you source impedance and noise.

The ultimate answer is here now but still expensive. This in theory will solve everything.

https://www.tesla.com/en_GB/powerwall

Lupus-Dei

Re: BMU Loan

Unread post by Lupus-Dei » Wed Feb 21, 2018 8:05 pm

Most interesting Richard, how many organs does this cost ?

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Dr Bunsen Honeydew
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Re: BMU Loan

Unread post by Dr Bunsen Honeydew » Wed Feb 21, 2018 8:15 pm

The basic single power wall without the solar power (pretty much a waste of time here) is £6k.

As I say, especially up in the hills in Wales I would fit a wind generator.

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karatestu
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Re: BMU Loan

Unread post by karatestu » Wed Feb 21, 2018 8:23 pm

Dr Bunsen Honeydew wrote:
Wed Feb 21, 2018 8:15 pm
The basic single power wall without the solar power (pretty much a waste of time here) is £6k.

As I say, especially up in the hills in Wales I would fit a wind generator.
Wind generator ? Thats me most days. I need a turbine on my back side ?

Seriously, i thought you needed an invertor to power things from the sun and wind ? Or are you suggesting running the hifi directly from the battery and cut out transformers and rectifiers. Might need a regulator depending on the voltage output of those telsa thingies.
Naim, Linn & Harbeth fanboy

scotty38
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Re: BMU Loan

Unread post by scotty38 » Wed Feb 21, 2018 8:28 pm

Alfi, I may have missed it in the various threads etc but have you considered the buzzing transformers could be dc on the mains? My boiler kicking in (most likely the pump) makes my power amp buzz but the worst offender by far is my wife's hair straighteners. Ridiculous when she has them on. A dc blocker in front of the BMU could well solve the issue....

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