mike stehr Posted January 19, 2003 Share Posted January 19, 2003 Last fall I scored a old Magnavox console with a SE amp for three bucks. The guy I know locally likes the SE 6BQ5 sound, so I seen this amp and bought it, 3 bucks ya know, why not? I wanted to just pretty much just go stock circuit with my limited capability, and mount a switch on the chassis.(which is about 5" X 8" BTW.) I drew Dan up the stock schematic and we talked about it on a visit. He drew up a quicky schematic eliminating quite a few parts(about ten), and using more capacitance in the cathode feedback circuit. So I went home and played around and cobbled it up, I had a good multisectional capacitor that he tested. I'm using .047 Sprague 716P for coupling caps. (I may get PIO's, but not at this time.) I visited him Yesterday and He put the amp on a scope and frequency generator. He checked it over, and played with the feedback circuit and got the thing tweaked in. It started roll-off at around 40 hertz but hung out there to 40 khz, nice top end. The amp put out 4.5 watts, and that was wide open. These output transformers are only 2" wide X 1 5/8" tall, and 1 1/2" deep, so the roll-off on the lower frequencies is expected. Then we hooked it up to his speakers, Sansui PCM 100 II's. There around 94Db sensitivity. OK, Dan is no esoteric super-fi kind of guy, he listens to his SE magnavox 6BQ5 amp with a digital cable box for a pre. His amp uses a 5V4 rectifier. Which was a 5U4, with a 12AX7 driver. The chassis on his is around 12" X 5" with larger output transformers, with a wider laminate stack. Mine uses a 6CA4, with a 6EU7 driver. The little amp has bass! Suprised both off us, we didn't think it would get down that low, his Sansui's are port tuned at 25 hertz. His amp had little more bottom end, but not by much. We broke it in for a good hour, it sounds great. I'll fire it up Tomorrow with the full Mullard compliment. It may be a homely little thing, but it sounds nice! Quote Link to comment Share on other sites More sharing options...
jazman Posted January 19, 2003 Share Posted January 19, 2003 Mike, That's what's called a lot of bang for the bucks. I'll bet it will sound even better when connected to your Cornwalls! Let's get that completed. Klipsch out. Quote Link to comment Share on other sites More sharing options...
Deang Posted January 19, 2003 Share Posted January 19, 2003 That's so cool Mike. No doubt, 4.5 watts of 6BQ5 is bound to sound good -- and at $3? Must be nice to have your skill-sets. Quote Link to comment Share on other sites More sharing options...
mike stehr Posted January 19, 2003 Author Share Posted January 19, 2003 It is a stereo chassis. Actually it's really around $23.00 with parts. Quote Link to comment Share on other sites More sharing options...
Deang Posted January 19, 2003 Share Posted January 19, 2003 $23? Man, what a rippoff. Quote Link to comment Share on other sites More sharing options...
mike stehr Posted January 19, 2003 Author Share Posted January 19, 2003 Yeah I know. I don't know how I'll make ends meet now. I picked up some cabinets for my Norelco 12" FR's from Dan Yesterday also. The Norelco AD 4201M has a range from 40Hz to 18,000Hz as claimed from the philips fullrange site. 10 watt power rating, 5 ohm impedance at 1Khz. 820 gram weight, binders on the frames. Good match for a little SE amp. The cabinets are three and a half feet internal volume, they need a little TLC and finish work. But they should be pretty nice looking cabinets. A baffle for the fronts and some new backs, vent tune them, and I'll be good to go. This amp has been going for around 4 hours or so, the power supply transformer barely gets hot, and it's quiet. Quote Link to comment Share on other sites More sharing options...
CaptnBob Posted January 19, 2003 Share Posted January 19, 2003 Don't sell the old Magnavox consoles short. I've got one that's bi-amped, with a Jensen horn tweeter and a 15" woofer, and considering what it's trying to do, still sounds quite creditable entering its forty-third year. I'll be interested in seeing where the Bose Waves are in 2045. Quote Link to comment Share on other sites More sharing options...
fini Posted May 5, 2005 Share Posted May 5, 2005 Mike, Does your amp look like this one? Quote Link to comment Share on other sites More sharing options...
mike stehr Posted May 5, 2005 Author Share Posted May 5, 2005 Same exact amp. It even has all the tubes, all I got was a 6EU7. Did you buy it? Is the console a little lowboy looking thing in red mahoghany? Quote Link to comment Share on other sites More sharing options...
3dzapper Posted May 5, 2005 Share Posted May 5, 2005 Knowing fini, it's probably the bottom console in a stack of twenty five in his garage. Mike, that amp is cute. some 1/4-1/2" wood epoxied to the front and sides, a little laquer thinner to clean those numbers off the PS tranny and a screen of some type over the finger (OUCH!) hole and it could be Front Row Mo. http://forums.klipsch.com/idealbb/files/wood.jpg Rick Quote Link to comment Share on other sites More sharing options...
fini Posted May 5, 2005 Share Posted May 5, 2005 ---------------- On 5/5/2005 7:22:50 PM 3dzapper wrote: Knowing fini, it's probably the bottom console in a stack of twenty five in his garage. ---------------- HEH! Bought it, pulled it, cleaned it, sh*t-canned the console already! So there! This might start a trend. I doubt we'll have much impact on the BlueBerry/VRD club, though... Quote Link to comment Share on other sites More sharing options...
mike stehr Posted May 5, 2005 Author Share Posted May 5, 2005 Yeah, I have 3 amps I need to gussy up. The wiring layout ain't nuthin' special, but it's quiet. I need better binding posts, and a chassis mounted fuse holder. But since it works fine, I haven't bothered. Gee Fini, that thing cleaned up pretty good! I guess I best draw up a schematic for ya.......... Quote Link to comment Share on other sites More sharing options...
3dzapper Posted May 5, 2005 Share Posted May 5, 2005 ---------------- On 5/5/2005 7:55:49 PM fini wrote: ---------------- On 5/5/2005 7:22:50 PM 3dzapper wrote: Knowing fini, it's probably the bottom console in a stack of twenty five in his garage. ---------------- HEH! Bought it, pulled it, cleaned it, sh*t-canned the console already! So there! This might start a trend. I doubt we'll have nuch impact on the BlueBerry/VRD club, though... ---------------- That looks like Mikes! Rick Edit: Mike these binding posts. are really nice for the money. I bought two dozen. Quote Link to comment Share on other sites More sharing options...
edwinr Posted May 5, 2005 Share Posted May 5, 2005 We just can't get cheap stuff like that in Australia. Anytime someone sells old tube gear, it's falls under the category of 'classic', or 'collectors', etc. So the dollar values goes sky high and the poor old hi-fi nut like me loses out. Quote Link to comment Share on other sites More sharing options...
fini Posted May 6, 2005 Share Posted May 6, 2005 Mike, Can I see a shot of your underside? Of your amp, I mean. Quote Link to comment Share on other sites More sharing options...
3dzapper Posted May 6, 2005 Share Posted May 6, 2005 Mike put it on the back page above. Magnavox SE 004.jpg It won't come forward because of the spaces in the title. Rick Quote Link to comment Share on other sites More sharing options...
fini Posted May 6, 2005 Share Posted May 6, 2005 Ah-ha! Thanks! Trying to figure out a power switch... Quote Link to comment Share on other sites More sharing options...
3dzapper Posted May 6, 2005 Share Posted May 6, 2005 fini, Don't do it exactly like Mike did. Put a fuse between the power cord and the switch. Rick Quote Link to comment Share on other sites More sharing options...
fini Posted May 6, 2005 Share Posted May 6, 2005 Yes, I will do that when I remodel it, but I wanted to be able to "fire it up" without "firing it up" (if you know what I mean...). I was thinking I could just "jump" it or something. Maybe use the wires going to the connector (that went to the tuner/preamp). My guess is that it's the 2 white wires. I will check in the preamp to see which went to the switch. Quote Link to comment Share on other sites More sharing options...
3dzapper Posted May 6, 2005 Share Posted May 6, 2005 You are right it looks like the white one and the off white one. You can watch the current on your new variac. Rick Quote Link to comment Share on other sites More sharing options...
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