Bryston 3B Pro restoration.

[GloBug]

I'm just starting a rebuild of an older Bryston 3B.
I got it for $30, apparently it had a bad channel. For the price I figured it was worth a shot, I could always use it for parts.

Before I tore it down I thought I would try it first, I did get sound out of both channels if I played with the power switch. So it looks like I might be in luck.

It's filthy and a little worn, it is well used. I would imagine it has been used everyday since it was new.

So I figure I will have at it, the problems might go away with a good cleaning.

I am going to re-cap the power supply, although I might use it for a bit with the old caps against my better judgement.

Anybody done any "upgrades" to their Bryston?

[nigelwright7557]

Electrolytics have the shortest life in an amp so they will need looking at first.

I would also clean out any fluff and dust to stop the amp overheating.

[GloBug]

Yes it is dirty. It takes multiple steps to get it clean. Goo-gone and then TSP. Sometimes I have to repeat the process.

OK so I checked the capacitors for fun. They read a little low, but seem to be functional.
My capacitor checker is the low voltage type. (BK precision 820), so I don't have a whole lot of faith in the test.

Now the filter caps are 7500uf+7500uf 50v in series for each channel. This gives ~3500uf @100v.
I wonder the reasoning for this? Simply to raise the voltage rating of available caps?

I guess I could just replace the 7500uf + 7500uf 50v's with a single 3500mf cap at 100V? (If available)

Not that I needs it, but maybe I could increase the capacitance while I'm at it.

[nigelwright7557]

High voltage large capacitors are expensive and more rare.

I wouldnt increase the capacitance too much or you might get switch on surge problems like fuses blowing. Perhaps 4700uf 100v as they are quite common.

[GloBug]

I just had a peek online.
Going with a 4700uf /100V looks like the way to go, there is lot's to choose from, I only saw one 7500uf so far.
Good to have some options. There is also some 3500uf 400v computer type caps that might be an option too.

[lanchile]

Bryston are very good amps. I would send it back to Bryston for a full check up. the service is excellent.

[GloBug]

I thought about looking into that. I am pretty sure it's older then 20 years though.
Either way.

[lanchile]

Originally Posted by GloBug

I thought about looking into that. I am pretty sure it's older then 20 years though.
Either way.

even if you have to pay to get it fixed from Bryston it will be worthy. you will get your amp new as it came from factory.These people from Bryston are top notch!!!!.
" hey and they are located near you lol."

[GloBug]

Sorry Lanchile, looks like I'm going the DIY route! You are right though.
I actually might see if I could get my own tour there one day, would make for an awesome road trip.

So I finally got the thing cleaned up. It sure was a lot of work. I have cleaned every part except the actual circuit boards. I will do them separately.

I fought in -20 weather inside of an improvised paint tent to get my polyeurea coating on. Barely got it done with out screwing it up. lol.

Here's a picture of the assembly started. I installed some new feet. If those Hammond transformers don't give you a hard-on there's something wrong with you.

[lanchile]

Originally Posted by GloBug

Sorry Lanchile, looks like I'm going the DIY route! You are right though.
I actually might see if I could get my own tour there one day, would make for an awesome road trip.

So I finally got the thing cleaned up. It sure was a lot of work. I have cleaned every part except the actual circuit boards. I will do them separately.

I fought in -20 weather inside of an improvised paint tent to get my polyeurea coating on. Barely got it done with out screwing it up. lol.

Here's a picture of the assembly started. I installed some new feet. If those Hammond transformers don't give you a hard-on there's something wrong with you.

Good for you GloBug. What kind of amp are you going to build with those transformers 70vac secondaries?

PS: I had a Bryston B60 before, but I sold it and went for a diy integrated amp. Happy as a clam!!!