Musical Fidelity B1 Schematic (does anyone have one?)

[Thomo]

I have just modded this great little amp, but would really love the schematic if anyone has one please?

I am particularly interested in the pre-amp section, if anyone knows of another MF amp that has the same preamp section, that'd be great.

Regards,

Lee.

 

[mikee55]

a possible link

http://www.georgeforeman.co.uk/?utm...tm_medium=cpc&utm_term=george foreman grill:D

 

[mikee55]

another, on a serious note.

http://www.fletchersite.com/

There are sites, some like this one

http://www.user-service-manuals.com/

http://hifi-wiki.com/index.php/Product_Database(maybe)


Sorry bout the grill pan, reminded me of the A1

Mike

 

[Thomo]

Re: a possible link

http://www.georgeforeman.co.uk/?utm...tm_medium=cpc&utm_term=george foreman grill:D

Mmmm, tasty bit of kit. Thanks, lol.

Lee.

 

[Thomo]

In all seriousness though, I am very impressed with this B1 amp. The sound is very open and clean and with great bass control.

I just managed to squeeze some Mundorf smoothing caps in there, which made a nice difference, I also changed the preamp section opamp to LM4562, which really improved the detail.

Cheers for the links,

Lee.

 

[Niggle]

B1 Scematic?

Hi Thomo

Did you manage to locate the schematics you were looking for?
The reason I ask is my B1 went 'belly up' at the weekend; I replaced the fuse at the back of the unit, it powered up, but no output.

I whipped the top off to find resistor R69 and one of the main electrolytic caps were touching and the resistor totally scorched - I am certain the resistor is open circuit, but no sure about the state of the cap - its marked and the plastic coating has partly flaked off but it looks OK.

Anyway, the resistor is too badly damaged to figure out it's rating, so I am trying to find a schematic to find out, once I have relpaced it I should be able to figure out the status of the cap.

I have tried following the links provided by Mikee55, but without any success.

Any help would be appreciated - cheers.

 

[Thomo]

I did finally manage to get the schematics yes.

I will upload them to my site and post links soon.

Cheers, Lee.

 

[Niggle]

B1 Schematics

Good news; I have scoured he internet and found nothing of any use.

I look forward to your link - if the schematic is readily accessible, can you advise the rating of R69?

Many thanksfor the help.

Cheers

Nigel

 

[Thomo]

Sorry it took so long, but I finally found it.

You can download the files here

Cheers, Lee.

 

[Niggle]

B1 Schematics

Excellent, just what I need - many thanks, very much appreciated.

Cheers

Nigel

 

[ekadek]

very interesting to find that B1 scheme. TA very very much. the one i got is great and ive always wondered how to set up the bias adjustments. anyone know a figure to shoot for.

 

[Thomo]

Hi, I'm glad you found the schematic useful.

I'm not sure of the correct bias value, but if your amp is still working well, I'd just balance the two channels to the same value (ie adjust one channel to match the other).

Have you changed any of the capacitors in your amp yet? Also, a fantastic mod is to upgrade the opamp in the preamp section, I used LM4562.

I'm going to have another look inside again soon as I'm using the amp again in my main system. It may not have oodles of power, but it'll drive anything as long as you don't need it really loud.

Cheers, Lee.