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Any Bedini Owners?

ddrjboo said:
I've never used them, but I've heard good things about Action Electronics in Williamsburg. Not sure what part of Virginia you are in.
Bedini products typically do not have service manuals available so they may be difficult to repair. It's a shame because they can sound very good when working properly.
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Much appreciated, I will check them out. I am in Harrisonburg Va but Williamsburg is not a bad drive. Music Technology in Northern Virginia was a great resource but they are no longer in business. Yes, John Bedini was very hard to get service information from. To make it worse, I don't think this amplifier ever made it into full production, so whatever differences exist between the BA-900 series and the BA-800 series amps is hard to determine except to compare them side-by-side or find a tech who is very familiar with the
BA-803.
Thanks
Wayne
 
I took some pictures of the BA-903 to compare with the BA-803. The fuse values are 5 amp on the 4 board fused, 15 amp slow blow on the power fuse
and 10 amp fast blow on the speaker fuses. The 10 amp seems very high on the speakers, but that is how John sent it to me. I also noticed the output
transistors are not all matched on the right channel. I am not sure if it was manufactured that way or John serviced them while he was using the amp.
The left channel is the one blowing fuses. No hum or pop through the speakers, the left channel just stopped working. I disconnected and replaced fuse
and it blew as soon as turned on.
The boards themselves are from the 803. The number is blocked out and "903 JB" is written on them in marker. The same notation is on the power transformer
and on the main capacitor plate.
Do any of you see any obvious issues visually? I don't want to pull it apart myself(not sufficient knowledge), but will try to get it to a tech who is familiar with Bedini amps.

Thanks
Wayne
 

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Here are a couple BA-803 amplifier pics I found on line for comparison.
Thanks
Wayne
 

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Hi!
I once heard that the 9xx series is the 220 Volt Version of the 8xx Series. There should be no other difference. Maybe they're higher biased? But in Europe the 9xx were sold later on.
 
Is it normal to hear a slight hum of the transformer hum in the speakers? My Bedini 803 does so. It's on both speakers and as soon as the music plays it's not present. Maybe on very silent parts it's hearable. Is that normal? A technician serviced the amp 2 years ago. Cleaning, thermal paste, setting BIAS to 35mA.
Thanks a lot!
C
 
Thanks for the response. I did not have any hum from my 903. I had a 200/200 that had a bit of hum, but not the BA-903. My amplifier is a 110 volt standard
U.S. version. Maybe John switched mine back prior to sending it to me.
Much appreciated,
Wayne
 
Thanks for the info. The hum got more over time. Maybe the filter caps of the transformer? The 803 has a slightly other transformer like like the 903. I hear my transformer humming inside the amp when I get there with my ear. Maybe some has an idea. Thanks
Coco
 
WAYNECAR said:
I took some pictures of the BA-903 to compare with the BA-803. The fuse values are 5 amp on the 4 board fused, 15 amp slow blow on the power fuse
and 10 amp fast blow on the speaker fuses. The 10 amp seems very high on the speakers, but that is how John sent it to me. I also noticed the output
transistors are not all matched on the right channel. I am not sure if it was manufactured that way or John serviced them while he was using the amp.
The left channel is the one blowing fuses. No hum or pop through the speakers, the left channel just stopped working. I disconnected and replaced fuse
and it blew as soon as turned on.
The boards themselves are from the 803. The number is blocked out and "903 JB" is written on them in marker. The same notation is on the power transformer
and on the main capacitor plate.
Do any of you see any obvious issues visually? I don't want to pull it apart myself(not sufficient knowledge), but will try to get it to a tech who is familiar with Bedini amps.

Thanks
Wayne
Click to expand...
The resistor between the fuse holders and the caps are not here in my 803. Maybe your technician can check the bias of the 903 on idle via the 0,47 resistor. Would be cool to know if this amp has a higher idling voltage. Normally it's about 16mV.
 
Which resistor? If I find a technician familiar with Bedini amps I will get some more technical data when I get them to work on it. John was not
very forthcoming about many technical specs. When asked, he would just say it would drive my speakers for all they were worth. They really did
that. I had some Phil Keck modified Acoustat 2+2's and the 903 made them sound great. They ran my Martin Logan SL3's very well also, but I
lost a channel prior to running with the Martin Logan Prodigy's I currently have in the system. They are being powered currently by a Classe DR-9
and it does a very good job driving the Prodigy's.
Thanks
Wayne
 
This is probably the dumbest question ever, so apologies in advance. I just came across a Bedini 802 amp, and have it paired with an Audio Research tube preamp.
Everything seems to be working well.
My questions is, if the amp (or preamp) get warm, will they lower the volume before they blow a fuse? The previous owner had a rather large supply of fuses that came with them and I am wondering if there is built in protection or if this is a problem with them.
 
Were the fuses all the same rating as the Bedini fuse or different ratings? I ask because I too have a large fuse supply, not because my amp blows fuses but they were purchased during Radio Shack's going out of business sale. I think they were a dime for each pack of 5.
 
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cascioman said:
This is probably the dumbest question ever, so apologies in advance. I just came across a Bedini 802 amp, and have it paired with an Audio Research tube preamp.
Everything seems to be working well.
My questions is, if the amp (or preamp) get warm, will they lower the volume before they blow a fuse? The previous owner had a rather large supply of fuses that came with them and I am wondering if there is built in protection or if this is a problem with them.
Click to expand...

Welcome to AK! (I see you've been a member for a couple of decades, but AK says this is you first post - yay!)

First, the obligatory "there's no such thing as a dumb question".

Alas, the preamp doesn't know what the power amp can handle. Not it's job. Whether the preamp gets hot or no should be independent of any characteristic of the power amp. (If that turns out not to be true, this is a really interesting and unusual issue.)

Do some power amps allow fuses to blow even if nothing is wrong? I think the answer is yes. Not sure if Bedini is one of those amps. If you have a multimeter, check whether there's DC voltage at the speaker outputs. If the DC voltage at the speaker terminal is near zero, you'te fine.
 
Thanks guys! The fuses upon further looking are random. The previous owner was probably a boy scout like me and liked to 'be prepared' and just put them all together for whatever he used them for over the years.
The main question i had was when I was testing the unit he had them stacked up on top of each other and they were working strong AF but after an hour or so when I turned up the gain on the preamp, the volume actually went down... then after separating the units and letting them cool, everything worked fine again.
So my question is, is there some kind of protection in the preamp (tube) or bedini amp that will limit the power? Again, no fuses blew and the volume didn't completely cut off, just lowered on its own.
Clear as mud?
 
Hi guys! Short question, if you replace the big can capacitors in the power supply, which one do you use? I have a BA 803 which uses 6 large caps. I have a slight hum which comes from the power transformer I think and hope this will fix that. Thanks in advance!
Coco
 
661-6D101LPN223TDA5U, I used these from Mouser for my BA-802, They are on B/O now. As I re-call there weren't a whole lot of choices that would fit at a reasonable price point. I would be pretty sure they are the same only you have two more in your unit. Measure to make sure, 2-1/2" x 4-1/8" 19,000UF (you can go up in UF) is what I would think you have in there.
 
Thanks mate! Did they change the sound of the amp or any characteristics? Did you also have some hum before you changed the caps? Thanks!
 
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I had a buzz noise. Before I changed the caps the bass was way too much and the rest was just ok. Afterwards the bass was correct with the upper end really good with improved mid range. I replaced the main filters and the three axial caps on each board. Adjusted the bias to 35ma (16mv across emitter resistor). I have to say I really like this amp. I wish I had your model but I’m good for now.
 
Thanks for helping me out! The editor resistors are the ones nearest to the transistors, right? I once read that John Bedini said "measurement" on the positive side. Thanks again!
 
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