New Alpair 7, small OB project

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Well, took the plunge 😱 and did a simple design of an L shaped OB panel to sit on my subwoofers made out of solid White Ash. Phil Townsend did all construction assisted by his shop slave 🙄. I did all the finish work using a black dye stain, Seal Coat then four passes of Behlen's String Instrument Lacquer. All work was done to optimize performance of the Alpair 7. They simply sound wonderful, in fact I would say they sound better in terms of height and width dispersion than the Maggie 1.6's that I once had not to mention they have beautiful tonality and that is only after 70 hours break in time. Here are a few photos.

Ramon
 

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Also, I should mention that Phil has built countless Full Range cabinets and is now focused on OB designs. No metal screws were used in this project just glue and wood dowels and rear speaker surround is tapered to allow more air on backwave.

Ramon
 
Hi Ramon - Very sweeeeeeeet! Did you build the subs yourself and if so how about some info on 'em? How are you doing your xover to the sub's and at what freq?

BTW - is that a HDD interface cable you are using to drive the 7's with????
 
c2cthomas,

Subs are the NHT Sub Two system with two 10 inch drivers driven with ( Sunfire/Carver plate amps @ 250 wpc @ 8 Ohms. Crossover is reversed phase at 130-150 Hz I believe, been moving it around as amp is slightly dull and room is heavily damped. Alpair currently run off a mid - Fi Marantz integrated full range. I am working on my Blue Circle BC2's as I am confident these will take sound too a far more intoxicating level directly to Alpair 7 full range. Current preamp is custom Perreaux SM2. I also have a restored custom Scott 222C that is spectacular, unfortunately this is on the bench as well. I 🙁 can never leave well enough alone) have to customize and that spells mistakes and learning curve without your favorite system at times, sucks. Cables are a DIY copper ribbon with long silver terminations, medical tape and cotton linen jackets.

lazyfly, yeah love the White Ash, real simple and beautiful stuff. Took dye, shellac and lacquer like a charm.

I will get more into sound disscussion as I swap in better gear soon and speakers break in more, but I must admit it sounds damn good even with this limited amp.

Ramon
 
Thanks for the info about the subs Ramon :cheers:
My reason for asking is that I'm looking for a starter project for a buddy of mine who is trying to get his kid interested in DIY and music - so I thought a little OB project would be a simple build - plus I've been wanting to try out some of Mark's speakers. Looks as if I'll need to keep looking for subs but for a simple and low cost starter project for a newbie I'll most likely go with a 15 inch woofer in an H-frame OB driven off some sort of BASH amp.

ps - I get the impression that you have been at this little hobby for a good while and have a high level of knowledge - after all - not many of us get to play around with Blue Circle BC2's for sport - but I did find this article about a guy (Charles Hansen) doing a bit of a tune-up on his Scott 222C and thought it might be of some interest to you. http://www.audioxpress.com/magsdirx/ax/addenda/media/hansen2642.pdf
 
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Alpair is wide open with no crossover, subwoofers have a controller and their own plate amps. From integrated I go line out too sub crossover/controller and directly off integrated speaker taps to Alpair 7. All is surprisingly seamless with no audible artifacts thus far. Hope this answers your question.

Thanks Scott, have liked your work😎: as I have heard some of your designs that Phil has made.

Ramon
 
Thanks for the info about the subs Ramon :cheers:
My reason for asking is that I'm looking for a starter project for a buddy of mine who is trying to get his kid interested in DIY and music - so I thought a little OB project would be a simple build - plus I've been wanting to try out some of Mark's speakers. Looks as if I'll need to keep looking for subs but for a simple and low cost starter project for a newbie I'll most likely go with a 15 inch woofer in an H-frame OB driven off some sort of BASH amp.

ps - I get the impression that you have been at this little hobby for a good while and have a high level of knowledge - after all - not many of us get to play around with Blue Circle BC2's for sport - but I did find this article about a guy (Charles Hansen) doing a bit of a tune-up on his Scott 222C and thought it might be of some interest to you. http://www.audioxpress.com/magsdirx/ax/addenda/media/hansen2642.pdf


Yes, I have read Hansen's work🙂 and it is interesting, Phil and I have been trying too track a hum in Scott 222C :headbash: :cuss: that is really testing patience but these amps sound incredible when renovated and tubed properly. BC2's have an output of 75 watts per mono block. I am currently replacing power supply caps and relay transistors I will then drop bias way down to run 😎 cooler and hopefully gentle enough to make Alpair 7 :sing: .
 
Ahhh – yes – troubleshooting old tube gear – always a great way to get a lesson in humility. Wires that become brittle from age and corrosion plus insulation that breaks down. The fun stuff has the woven cloth jacket over asbestos insulation – usually around the transformers and high power tubes.

The really hard to find “hummers” can be caused by transformers that will test ok – but are really passed their prime and need a replacement – or – and this is a good one – a bad tube socket. Those suckers can breakdown over time and cause problems. It is rare that such a thing happens – but it does.

I could list a buncha suspects – but with your experience I’m sure that you and Phil have gone thru most of the stuff I would list off.

Good luck – and keep one hand behind you when you are probing around in there!!!
 
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