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Info Wanted: Reference: 450R by Quadraflex Stereo Receiver

Quadraflex45

Quadraflex45

Member
Hello AudioKarma! I wanted to start this thread because there isn't much information out there on Pacific Stereo or Quadraflex. I have always liked the looks and sound of the Reference: R series receivers. (085R, 180R, 200R, 300R, 450R, 650FETR) And would like to know your experience with them if you ever used one or owned one. Or if there are any manuals or schematics for these out there. Also if anyone knows where I can get lamps for these, please let me know! If anyone has any good memories of Pacific Stereo, Feel free to post them! -Quadraflex45
 
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I have a 450r and love it but it has an issue right now. It has a couple transistors I need to replace that are failing. When I originally got the 450 it had a blown final and a couple burned resistors. Repaired that then the phono board went bad and I repaired that. As.far as sound when I have listened to it I think it's great, maybe the best receiver I have but I need to get this last issue fixed so I can compare it more.

I also have a 650 that has issues that I'm trying to repair right now but since it has mosfets it's a new learning curve for me.

I love the looks of the refrence series and would like to own all of them just for the heck of it.

As far as manuals and schematics there aren't any. I've contacted the Pacific Stereo guy on this site and he said service manuals were never released for Quadraflex.
 
Thanks for responding! My 450, my dad bought new at Pacific Stereo in 1977 or 78. My 450R has never been serviced, and is still going strong! The MOSFETS can be ordered on ebay. Hmm...I wonder why they never released a service manual for the Quadraflex? And yeah, the Reference series is VERY rare too! I love the looks, really stands out because most other receivers had a silver face. Have you had any dial bulbs go out yet? My 450R has 2 bulbs out, each on the end of the dial. The middle ones work, and the meters work too. Do you know what type of bulb is in the dial pointer? Mine light up, I just wanted to know in case it ever goes out.
 
I think the finals are ok in the 650. It plays but has a hum in both channels. I'm having trouble finding someone who can tell me how to set bias on this receiver since it has mosfets.

I don't know what the dial pointer bulb is, I haven't had to mess with that.

On my 650 I have to replace all the dial bulbs. Someone has been in it before and Jerry rigged some replacement lights that aren't correct.

When the 450 was working I liked the sound of it better than my Sansui 8080.
 
Yeah the hum could be bad filter capacitors, you might want to check those, or it could be some noisy transistors in the amplifier section. You can ask AK user PacificStereo for help biasing it. He is an expert on the Reference: series units as he worked as PS. How is work on the 450? It seems burned/open resistors are common in these receivers.
 
I've asked Pacific Stereo for help but he says those receivers haven't crossed his bench so he can't help me.

The 450 is pretty easy to work on. Seems to be pretty basic to me, and yep the left channel had burned open resistors when I got it also.
 
Hmm I thought PS worked on a 180R once.... I wonder what caused those resistors to open up? So like I said, you should check your 650 for bad filter capacitors.
 
I believe the dial lamps are 8 volt 250ma. I could not find originals for a reasonable price, so I used wedge lamps. See here.

The pointer lamp could be impossible to find. It may be a tiny LED, I don't know.

I have had a 180R and 300R and still have a 650FET R. I had to replace the outputs on the 300R, which are NLA, so another mod was needed.
There is a thread around here somewhere about it.

Rob
 
There are about three transistors for which I cannot find a workable replacement.

One is a 2N5436. It is a high current TO-3 PNP germanium with 60 mil pins.

Light bulbs can be replaced with LEDs if nothing else.

You are OK.
 
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