Hi djk,
I can't remember the BGW 500 in particular. What was the issue with the 5 1/4" model? Overheating?
-Chris
I can't remember the BGW 500 in particular. What was the issue with the 5 1/4" model? Overheating?
-Chris
I have some BGWs from the Rock and Roll days. The circuit boards look like they were layed out with a hatchet.
But, you know... they still work! 250 Watts of ear grinding torture.
But, you know... they still work! 250 Watts of ear grinding torture.
Hi poobah,
I can think of some worse sounding amps. They're all dead now (thank goodness!)
-Chris
I can think of some worse sounding amps. They're all dead now (thank goodness!)
-Chris
krmaudio said:
Sorry, shipping cost too high but perhaps some other takers? Cheers!
AndrewT said:
That's the spirit! Wrap it well and ship it bulk on a train or something?
anatech said:
At home here with my DC300A I actually ordered the output transistors last week. I should see them after Turkey Weekend! I'll have some more to post soon. Chris, I'm stilll looking for a local DC300A to ease my build. Keep your eye out.
Shawn.
"I can't remember the BGW 500 in particular. What was the issue with the 5 1/4" model? Overheating?"
Yes, the heatsinks had poor orientation for passive air-flow. The 7" model had the same chassis and heatsink as the 750. The 500 would put out the same power at 16 ohms as the 750, so it ended up on HF horns alot.
The 1000 had five pair of selected (for 170V ) 2N6259 per channel, 250W SOA at 100V (the MJ21194 only has 200W SOA at 100V)!
Yes, the heatsinks had poor orientation for passive air-flow. The 7" model had the same chassis and heatsink as the 750. The 500 would put out the same power at 16 ohms as the 750, so it ended up on HF horns alot.
The 1000 had five pair of selected (for 170V ) 2N6259 per channel, 250W SOA at 100V (the MJ21194 only has 200W SOA at 100V)!
Hi djk,
Thank you.
Hi Shawn,
Cheers!
Thank you.
That explains why I haven't seen any / many. I don't remember those specifically. In truth, I have to say that about most of the average amplifiers I worked on. Nothing to make them noteworthy.
Hi Shawn,
I told you I would. 😉 Many of those have passed through my hands as repair jobs. Then back to their owners. If you find one, you may find a bunch. I wouldn't mind playing with one. Still, a BGW 750C would excite me a lot more.
Cheers!
A new Driver PCB for Crown DC300A
I cooked up some pcb's last night to replaced the crown boards. The driver board is almost the same as the orriginal but I tweaked a set of pads for the new potentiometers to fit. I made some output boards but when I compare them to the orriginal Crown's, jeez the copper is so thick on them, I gotta keep them! So I'll strip them and remove the flux and gunk and I'll plate them with tin and they should look good as new.
Looking closer at the components on the orriginal Crown driver board, I just have to tip my hat to those folks back in the 70's because the components are top notch. Most caps are film foil or Mica. The mica's are 5% or 2% tolerance.
More to follow...
Shawn.
I cooked up some pcb's last night to replaced the crown boards. The driver board is almost the same as the orriginal but I tweaked a set of pads for the new potentiometers to fit. I made some output boards but when I compare them to the orriginal Crown's, jeez the copper is so thick on them, I gotta keep them! So I'll strip them and remove the flux and gunk and I'll plate them with tin and they should look good as new.
Looking closer at the components on the orriginal Crown driver board, I just have to tip my hat to those folks back in the 70's because the components are top notch. Most caps are film foil or Mica. The mica's are 5% or 2% tolerance.
More to follow...
Shawn.
Attachments
Poor pics
Yeah thats pretty bad. 😉 Perhaps Santa will give me a nice SLR with macro options and a real tripod for Christmas this year? While I'm at it, I need a new color laser printer.
Can the ol fart do any thing for the shakes?
I'll post better pics tonight when the 3 piece set is done.
Shawn.
AndrewT said:
Yeah thats pretty bad. 😉 Perhaps Santa will give me a nice SLR with macro options and a real tripod for Christmas this year? While I'm at it, I need a new color laser printer.
Can the ol fart do any thing for the shakes?
I'll post better pics tonight when the 3 piece set is done.
Shawn.
Hi Shawn,
I used to use 2N3440 and 2N5415. I think they are still available.
MJE340 and MJE350 will work.
-Chris
I used to use 2N3440 and 2N5415. I think they are still available.
MJE340 and MJE350 will work.
-Chris
Looks good and no pin-out changesanatech said:
I can still use the round hat type heat sinks on them.EchoWars said:
More money perhaps? Zetex = High -end? Do they fab or package select die components. They are mentioned often around here but I have never seen.
anatech said:
The Zetex are TO92 and would not dissipate heat as well as the TO39.
Shawn.
Zetex = British. High end? As opposed to what? Low end? I'm confused...
Those small critters can dissipate 1W, just like the originals, and you can put TO-92 flag-type heatsinks on them if you're overly concerned.
Those small critters can dissipate 1W, just like the originals, and you can put TO-92 flag-type heatsinks on them if you're overly concerned.
RE: BGW's
Chris, I may be coming into possesion of some BGW amps soon. If it works out should I shoot you a note?
Chris, I may be coming into possesion of some BGW amps soon. If it works out should I shoot you a note?