In time I have received a lot of mails regarding the replacement PCB I once made for Akai AT-93. At that time the AT-93 was relatively new but it had some design weaknesses. I designed the PCB for a better and separated power supply of Akai AT-93. I do not have the schematic but you can re-use most parts of the old PCB and you will have to buy some 7815, heatsinks for those and some caps.
Well, today I found the film for making the PCB. It is a PCB in the same shape as the original with some extra 7815( display etc have their own regulator 7815 ) and extra decoupling. The tuner really performs better with this power supply PCB.
If somebody is still interested they can have the film providing:
- everybody can use it, so when a fellow DIYer wants the file please scan it and mail it.
- I get a PCB made with my own film.
Well, today I found the film for making the PCB. It is a PCB in the same shape as the original with some extra 7815( display etc have their own regulator 7815 ) and extra decoupling. The tuner really performs better with this power supply PCB.
If somebody is still interested they can have the film providing:
- everybody can use it, so when a fellow DIYer wants the file please scan it and mail it.
- I get a PCB made with my own film.
If you're looking for a very good vintage (mono) tube FM tuner and can't afford a $1,500.00 REL Precedent there is a "sleeper" you can buy dirt cheap on ebay: The NATIONAL CRITERION. Ugly and bulky (National made big communication receivers) but an outstanding performer. (One of the most sensitive tube FM tuners ever made). Will far outperform any QUAD or LEAK tube tuners. Strange "futuristic" (then) look you'll love or hate. Usually sells for less than 70 $ on the well-know auction site,which is a real bargain.
tc-60guy said:
Here it is... The blank plate at lower right was for the (optional) Horizon 5 preamp module. Sensitivity was quoted by NATIONAL as 0.5 µV for 20 dB quieting and capture ratio 0.8 which was (and still is) exceptional for a tube tuner. Don't know if these specs were really met but this tuner performs very well even with a short wire indoor antenna. Complete review can be found in the September 1955 issue of RADIO-ELECTRONICS.
Attachments
I can highly recommend the Grundig FineArts T9000. If I remember correctly, this tuner was also highly rated in Stereophile. Well made and really good sound. I sometimes use it to record music to CD's and, with the better stations, the results can be astonishing. If you can find a well kept unit for a decent price, get it.
Kurt
Kurt
After seeing the picture posted by Forr, I went snooping around for a Sansui TU-555 and found a nice, clean one on E-pay. It replaced a run-of-the-mill Denon digital tuner. I must say, the old discrete analog tuner really kicks the digital tuner's sorry behind. The sound is much more lively and up-front, and I'm enjoying listening to the radio again. The Sansui looks striking in a dimly lit living room. The tuner came with a manual, so most likely, I'll be snooping around and doing some re-capping and perhaps some mods to the audio output chain.
Who's the best person to contact to have the tuner professionally aligned? The dial is a little off, and the quieting isn't quite what it should be, even with a strong signal. BTW, tha Sansui really pulls in the stations, even using just the cheap 300 ohm standard issue dipole.
Who's the best person to contact to have the tuner professionally aligned? The dial is a little off, and the quieting isn't quite what it should be, even with a strong signal. BTW, tha Sansui really pulls in the stations, even using just the cheap 300 ohm standard issue dipole.
The FM3 had an incorrect FM de-emphasis curve, a quick Google should produce the necessary fixes.
I love the old Scott tuners, though mine is temporarily borked from too much playing around.
You need to bookmark the 'Exclusively Sansui' page, where you'll find all the die hard Sansui-o-philes;
http://www.audiokarma.org/forums/forumdisplay.php?f=39
For repairs/etc contact Mark at Absolute Sound Lab
http://www.absoundlabs.com
I worked for Mark 25 years ago. He's the best there is when it comes to tuners; a true artist.
http://www.absoundlabs.com
I worked for Mark 25 years ago. He's the best there is when it comes to tuners; a true artist.
I have several tuners, and one I think very highly of is the Kenwood KT-8005 which is a 5 gang tuner that sounds very good and has excellent RF performance as well. (Single IF however)
I also have its little brother the KT-6005 which sounds almost identical, has 4 gangs and has good RF performance, but not in the league of the 8005.
Other recommendations would be the Mitsubishi DA-F10 - I have a not so mint one, near excellent RF performance, and two IF selectivities.
I've also got a McIntosh MR-71 (tube) owned for the last 26yrs or so, but while very nice I much prefer the KT-8005.
And a Fisher FM-50B (tube), poor on the sensitivity and selectivity, but quite nice sounding.
Tuners I have worked on in the past and like a lot would include the Fisher FM-200B, and the FM-100B. The Mitsubishi DA-F20 by all accounts is excellent and has been cheap lately. It's on my list to acquire at some point.
The FMtuner group on yahoo and The Tuner Information Center (TIC) are great places to get the score on a lot of different tuners.
Tuner Information Center - Vintage Stereo Tuners
I also have its little brother the KT-6005 which sounds almost identical, has 4 gangs and has good RF performance, but not in the league of the 8005.
Other recommendations would be the Mitsubishi DA-F10 - I have a not so mint one, near excellent RF performance, and two IF selectivities.
I've also got a McIntosh MR-71 (tube) owned for the last 26yrs or so, but while very nice I much prefer the KT-8005.
And a Fisher FM-50B (tube), poor on the sensitivity and selectivity, but quite nice sounding.
Tuners I have worked on in the past and like a lot would include the Fisher FM-200B, and the FM-100B. The Mitsubishi DA-F20 by all accounts is excellent and has been cheap lately. It's on my list to acquire at some point.
The FMtuner group on yahoo and The Tuner Information Center (TIC) are great places to get the score on a lot of different tuners.
Tuner Information Center - Vintage Stereo Tuners
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Must say I think the reputation of the Leak Troughline is rather exaggerated.
I have lots of them and have built several stereo decoders for them over the years of various designs. Whilst they are superb for their day and a lovely piece of engineering (by far the best around in the early 60's in the UK) I have never managed to get the performance levels that HiFi World magazine raved about....
The Leak Stereofetic solid state tuner is better in every area (IMHO) and they are still cheap and plentiful. Even this can't compete with my more modern Japanese tuner though.
I have lots of them and have built several stereo decoders for them over the years of various designs. Whilst they are superb for their day and a lovely piece of engineering (by far the best around in the early 60's in the UK) I have never managed to get the performance levels that HiFi World magazine raved about....
The Leak Stereofetic solid state tuner is better in every area (IMHO) and they are still cheap and plentiful. Even this can't compete with my more modern Japanese tuner though.
dyna FM3
I have a Dyna FM3, don't bother, it is a waste of money after 1970. I replaced it with a GE pocket radio about 1980 and never looked back- it is not prestigious, but it sounds better and has better reception without an external antenna. With the way electrolytic capacitors dry out, I'm now using a Sony Walkman pocket radio, it doesn't have the sensitivity of the GE though. I love my Dyna PAS2 preamp and ST70 tube amp, use my Dyna ST120 transistor amp despite occasional flame events, but the FM3 is retired to the basement permanently.
I have a Dyna FM3, don't bother, it is a waste of money after 1970. I replaced it with a GE pocket radio about 1980 and never looked back- it is not prestigious, but it sounds better and has better reception without an external antenna. With the way electrolytic capacitors dry out, I'm now using a Sony Walkman pocket radio, it doesn't have the sensitivity of the GE though. I love my Dyna PAS2 preamp and ST70 tube amp, use my Dyna ST120 transistor amp despite occasional flame events, but the FM3 is retired to the basement permanently.
Revox B760
Hi Ray
I just bought the Revox 760 ( 225,- EUR)
and i need to know what capacitors you replaced in the signal path?
I have planned to replace the LM301's with OPA 627 and of course the electrolytic capacitors in the power supply (very important)
At the same time I will replace the capacitors C9+C15+C16+C31+C3+C10
to 2,2mfd - 100V polypropylene types
Sincerely
Gert Mikkelsen
Denmark
Hi Ray
I just bought the Revox 760 ( 225,- EUR)
and i need to know what capacitors you replaced in the signal path?
I have planned to replace the LM301's with OPA 627 and of course the electrolytic capacitors in the power supply (very important)
At the same time I will replace the capacitors C9+C15+C16+C31+C3+C10
to 2,2mfd - 100V polypropylene types
Sincerely
Gert Mikkelsen
Denmark
Hi Gert,
I replaced the tantalum caps where possible with polystyrene caps. I don't recall exactly where. I had a lot of polystyrene caps, up to 1 mfd. The problem was that the polystyrene caps are so much larger than the tantalum caps and they often wouldn't fit in the space on the pc board. For example, I have some 5mfd plastic caps, but they are about 25MM diameter by 75MM long, so there is no way they would fit in the space of a 5mfd tantalum cap.
Ray
I replaced the tantalum caps where possible with polystyrene caps. I don't recall exactly where. I had a lot of polystyrene caps, up to 1 mfd. The problem was that the polystyrene caps are so much larger than the tantalum caps and they often wouldn't fit in the space on the pc board. For example, I have some 5mfd plastic caps, but they are about 25MM diameter by 75MM long, so there is no way they would fit in the space of a 5mfd tantalum cap.
Ray
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