View Full Version : Nakamichi / BGW ??

04-27-2007, 10:16 AM
I found this on an audio forum. Does anyone know if its true ? Are they 2 different products or merged ?

"Originally posted by Jane Spellman
I don't know much about the Crown pro amps but I recently heard a BGW pro amp driving Martin Logans (very revealing speakers) and I was shocked at how good that amp sounded. Everything I have ever read or heard about pro amps was that they all had great bass but were thin or bright in the midrange and high end.

This is not what I heard from the BGW amp. Top end and midrange were totally flat and transparent. Ditto for the Carver pro amps (although these are digital).

I have heard several amps in my system driving my Maggies so I am not of the "all amps sound the same" club but I will say that amp differences are subtle and not dramatic. Maybe what we are hearing from these pro amps is the dramatic advantages of having MASSIVE power reserves. My friend's BGW amp pumps out 600W/channel on his Martin Logans.

Sorry for such a late response to your earlier post but I just had to respond to your info on the BGW amplifier. You see, while I was in college I worked in the Engineering department of BGW. This was many years ago of course but I still remember it well. The company was in Hawthorne California. Factory, engineering, front office all in one building. It was never that big an operation.

Do you remember which model BGW amplifier you heard? If it was a BGW 750, then you are correct about the flat frequency response and massive power reserves. The BGW 750 had a massive linear power supply with huge capacitors on the +/- rails (I think it had two 150,000 uF capacitors each roughly the size of a peanutbutter jar). That amp was almost completely flat right down to 20Hz as well. It had excellent low end response (not surprising since BGW got it's start supplying the amplifiers for the movie Earthquake).

I put together their first automated test set and one of the biggest problems getting accurate power and THD measurements at full power was keeping the A/C mains from dropping below 115VAC when pumping a 20Hz sine wave just below clipping level into a 4 Ohm load. We basically had to have a variac to compensate for the A/C line drooping. They pull that kind of power from the A/C mains.

Anyway, thanks for bringing back some old memories. BGW was bought by Nakamichi (sp?) shortly after I left and ceased to exist some time after if I'm not mistaken"

04-27-2007, 05:47 PM
Interesting post, I have been a BGW fan since the seventies, these are one of the cleanest sounding amps that I have heard, even to date. I coppied and built 2 BGW 250D's years ago and used seperate torrodials for each channel and just recently purchased a 750D from ebay. These amps have tremendous power reserves and produce strong solid bass along with good clean transients. I also played with and built in prototype form a BGW 202 preamp which I would say is again one of the best sounding RIAA sections ... I have heard to date with unique circuit topology for the time. Not bad for stuff that was designed in the seventies, the BGW engineering team really did know their stuff !!! this vintage gear really is worth collecting.


scott fitlin
04-27-2007, 05:55 PM
Yeah, BGW was great stuff. Brian Wilson engineered those amps to be clean, and always overbuilt his power supplies.

The 750 is one of the best amps out there, for any use. I personally love the old 750B. The D and E are excellent amps too.

04-27-2007, 06:39 PM
Thanks for your comments, I don't know much about the history of BGW or who's who there. But this stuff was built back in the good old days when engineering Dept's ran the show and marketing did what they were told, these days I think marketing and the bean counters tell engineering what to do, so many compromises. I've seen this engineering loss of control in several areas since the late seventies, with marketing or production pulling the strings.

04-28-2007, 02:50 PM
Yeah, BGW was great stuff. Brian Wilson engineered those amps to be clean, and always overbuilt his power supplies.

The 750 is one of the best amps out there, for any use. I personally love the old 750B. The D and E are excellent amps too.

Actually it was Brian G. Wachner...;) He succumbed to leukemia in the 90's :(

They are now owned by Amplifier Technologies.
I've been using and repairing BGW gear since the late 70's -- I still like it!

04-28-2007, 04:06 PM
The 750 is one of the best amps out there, for any use. I personally love the old 750B. The D and E are excellent amps too.

If anyone ever spots a nice 750 B , C or D that they arent picking up, please let me know. My 250d is just fine, but I would like to try the 750 series.


scott fitlin
04-28-2007, 04:07 PM
Without a doubt, the BGW,s stand the test of time, still great amps.


I stand corrected on the name, though.


07-30-2009, 10:06 AM
Hello All,

I know this is an old thread but . . .
I am sitting in my studio listening to a vintage BGW 750E that sounds beautiful on my stock Yamaha NS-10M's.

I have checked through this amp and the only thing I can find wrong is the fan defeat will not defeat the fan, it runs wide open all of the time. I'm using balanced 1/4" inputs and have disabled the ground switch to achieve totally silent operation with the inputs wide open. It looks just as you would expect an amp this age to look, scratched up some but no excessive dings.

Obviously I can't push this thing really hard without shredding these little speakers but the meters are registering beautifully, and everything fully lights up just as it should when you power this puppy up.

The amp was a gift to a youth summer camp I am involved with in eastern Tennessee and I am trying to turn it into something useful for them.

If anyone is interested please PM me and I will gladly supply pics, serial #'s and whatever else I can to help this camp out.

Wish I could keep this thing, the imaging is beautiful and it really wouldn't be to hard to defeat the fan if I deemed it necessary . . .

Care to help some deserving kids out and acquire a classic amp in the process anyone?


07-30-2009, 10:20 AM
Wow,,this is an old thread.

I acquired my 750D quite a while ago....it had a similar fan problem ....wud only run full wide open , the SLOW setting didnt work.... opened it up, nothing obvious..located the p/n for the switch , but cudnt find the part.

Ended up pulling power to the fan and mounting a muffin fan the the rear , wired thru a speed controler...so I can dial in the highest speed with the lowest noise audibility :bouncy: