ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
Hi,
I inherited a BeoVision Avant 32 VCR which was in need of work such that it wasn't financially viable. (A lot more than getting a replacement off eBay!)
I hated to see it go to waste so I removed the speaker housings and the two amplifier boards, with the intent of re-using them to make a high quality sound system.
Does anyone have details of the power requirements for the amplifiers please, and pin-outs for the amplifier board inputs?
The amps power up with a nice healthy thud when I use a 12v supply, but I see that the on-board STK4122 II is happy with 17 - but I don't want to push it.
As for the inputs to the amps, I don't know if these are analog or digital - the latter might scupper my plans! Any information / interface specs that someone would be willing to provide would be most appreciated.
Thanks in advance,
Mark
I believe there was a similar project going on for the Avant a few months ago on the forum.
Have a search and see if you can find it.
Ben
Hi Mark,
Welcome to beoworld.
I'm sure there were also some similar projects in the archived forum so worth searching there too (click on the Archived forum button at the top of the page). From memory you'll need a -20V/0V/+20V power supply plus an input to disable the muting circuit.
From an audio perspective, the amplifiers themselves take an analogue audio input so there should be no specific issues there.
Uprading your beoworld membership to (at least) Silver status gives you access to the service manuals which should help too.
Hope this helps,
Martin.
Thanks Ben.
Following another post I tracked down the maintenance manuals... it looks like it shouldn't be too scary.
If I get it working I'll post details to the forum. Such a shame to see good sound heading to the tip!
I agree, I adore my Avant and the sound is truly incredible even by today's standards!
Best of luck and keep us posted!
Thanks Martin.
****
Thankfully it looks like I scavenged the right bits, apart from the PSU, but I can arrange for something with that.
If I get this working to my satisfaction I'll post something to the forum explaining what I did. As I mentioned to someone else who replied, it's a shame to send such a fine sound system to the tip.
Cheers,
*** Edit by Dillen
Beoworld moderator
Beovision 12-65 NG, Beosystem 4, Beolab 7.2, Beolab 6000, Beolab 5, Beolab 4000, Playmaker, Beogram 5005, Beo4, Beo5, Beovision 7-32 MK3 (2x), Beovision 4.42, Beosystem 2 HD, Beolab 7.1, Beolab 7.4, Beovision 10-32, Beovision 6-26, Beosound Moment, Beosound 2300, Beosound Ouverture, Beogram TX2, Beogram 2404, Beomaster 3002, Beovox CX 75, Beovox CX 100, ibundo, Keyring.......
No pictures just yet but there's progress.
My big issue has been with sourcing the +/-20v power supply so, thanks to PoundLand and £2 invested in four 9v batteries I have a temporary knock-up with sound coming out!
I'll sketch the circuit once I'm totally happy with it and post it and a few photos. It's not that bad once you've a stable PSU.
I have a couple of spare PCs, each of which contains an ATX PSU capable of delivering +/-12v. With some modification (GND is earthed) it should be possible to run these in series, and put the -12 -> +12 output of each of these through a regulator to bring them down to 20v each. Either that or I'll release the blue smoke from the components and they won't ever work again, or wake up on hospital with bits of PSU embedded in my face.
It'll be worth the risk for the sound. :)
Hi
I've also got an avant in my in-laws garage waiting to be pulled apart, so I'm very interested in what your doing.
Would one of these work for power?
http://www.maplin.co.uk/p/lenovo-ac-adapter-65w-20v-includes-power-cable-r50df
Steve
BV 11 46 Avant 32 VCR
Hi Steve,
That PSU might be suitable. It's only giving half the voltage that the amplifiers are documented as requiring though.
I've just managed to get the thing working using an old desktop PC ATX PSU, running the amplifiers at 24v rather than 40v. (I was planning to open a couple up, modify them and run them in series to give the full 40v, but if they work at 24v and I don't have to crack open a safely enclosed PSU and fiddle around with its entrails before plugging it into the mains, I'm happy with that.)
Perhaps it'll work, just give it a go. (Disclaimer - it's not my fault!)
Idle, the two amplifiers together are drawing 50mA. As loud as I want it on my desk it was peaking at around 190mA, but that was using a digital multimeter with a slow sample rate and I may have missed something higher.
The audio connector shown on the schematics indicate that it requires a GND connection. I found that connecting this to the PSU's GND connection (when I was running with batteries and had a +20/gnd/-20v supply) drew so much current that that the multimeter couldn't read it and the batteries got quite warm. It works quite OK just pumping the audio in without a GND connection.
If I can work out how to, I'll upload annotated images of the connectors.
Mark.
OK then - the audio connector.
As I mentioned, I've NOT connected the Audio GND to the PSU GND. It pulls too much current and it doesn't appear to be necessary.
The connector has two sets of four wires, one for each amplifier;
On the photo I've got a couple of yellows and a black carrying Audio L, Audio R and Audio GND.
Power connector.
Four lines, two for each amplifier.
The outer wires of the bunch of four have a white stripe on them. These are the PSU's 0v. The central solid-black two go to the PSU's +ve connector.
Anyone wishing to use an ATX PSU for this, here's the pinout of the connectors...
http://pinouts.ru/Power/atxpower_pinout.shtml
I'm running mine off the +12v and -12v connectors. Note that you have to connect pin 14 to one of the GND outputs of the PSU to turn it on.
Oh, and DO NOT rely on the colour coding! Use the pin positions and then cross check with a volt-meter to ensure you're connecting to the right ones.
I hope that this has been of use and will bring many hours of auditory pleasure to anyone wanting to have a go.
Its amazing, this is exactly the project I'm putting together
Did you have any luck with this project.
I recently ressurrected a the speaker and the amps from a Beovision Avant 32' CRT VCR. I'm wanting to use them to attachedto a CD player.
THerefore need to attach power and work out how to attache the CD.
THe CD player only has RCA plugs that I would have to make some inputs into the amps for.
If you have procedures and photos, that would be great
d
The project got to the point where with mine is shown above. I've used a PC PSU -12v/GND/+12v to provide the power but that's a little naughty and I really need to source a decent PSU as the -12v on the PSU isn't really supposed to have much current drawn on it.
The bits are now on the shelf, along with many other uncompleted projects, but the photos and annotations above should be a good point where you can put power and audio L/R in and get a chunky sound out. Thank you for the prod though. I really had ought to get on with this and finish it off.
After years of earing me saying how fantastic my B & O tv was, my best friend bought a used grey Avant 32 VCR (from my B & O store).
He really enjoyed it for years and years but a few months ago my best friend kids (or young mens) started to talk about how a 4k tv would be great with the GoPro shootings, blablabla...
While I was at his place not so long ago we talked about tv's and we had a look on the internet for the sales.
My best friend wanted to spend the minimum and we found a Polaroid 4k 55" for 600 €.
He bought the tv and needed a furniture to put it on but that was too much money.
So he got the idea of hang it on the Beovision Avant that he had dismantled and use the speakers.
I can't tell you how he did it but after a few weldings and spending a little more than 4 € on a electrical part the tv is fonctionnal (he gets the sound of of the Avant speakers while watching the Polaroid tv).
The only thing not working yet is the motorised stand but he thinks he's going to make it work.
Voilà.
I don't have better pics and my friend is in Spain right now. Cannot ask any question.
Check this thread: http://archivedforum2.beoworld.org/forums/p/1290/200937.aspx#200937