Braun had a presence here in Canada. Really nice stuff. In general, the larger the box, the better and more efficient the speaker is. If the woofer covers the entire baffle, the box is way too small.
CD-4 albums need a special processor and cartridge with response up around 40 KHz for the pilot.
Honestly, avoid quad receivers at all costs. Marantz included. I have a 4300 I'm not looking forward to repairing. I'll sell it. The amplifiers and other circuits are crammed and not very good compared to the stereo equipment. If you find a 2325, grab it. That is a super receiver. Blackout dial. I'm just about to work on another for someone.
For turntables, you want a Thorens, like TD-160, 125 MKII or better, TD-126 MKII. Wall mount recommended if you aren't on a concrete floor.
CD-4 albums need a special processor and cartridge with response up around 40 KHz for the pilot.
Honestly, avoid quad receivers at all costs. Marantz included. I have a 4300 I'm not looking forward to repairing. I'll sell it. The amplifiers and other circuits are crammed and not very good compared to the stereo equipment. If you find a 2325, grab it. That is a super receiver. Blackout dial. I'm just about to work on another for someone.
For turntables, you want a Thorens, like TD-160, 125 MKII or better, TD-126 MKII. Wall mount recommended if you aren't on a concrete floor.
I do remember "Sendust" - what a brilliant marketing name, really sounds like something, doesnt it?
When I worked at Olson's as a floor salesman in college, they had their fairly high end Fisher 3 head cassette deck. Used to play with the various tape formulations they sold, going back and forth between "Live and Memorex" using the tape monitor button. The tape that was the most audibly transparent was this mediocre Scotch FeO2 product, for some reason. Switch from line-in to playback head, could barely hear any difference. Why was that? One would think the better formulations like CrO2 and TDK-SA would sound more transparent, but they didnt.
I'm pretty sure Dolby was off. Never figured out that one.
Well, real CrO2 is an industrial abrasive. It is called "lapping tape in a box" and will wear heads rapidly. We could easily see customers who used Memorex. TDK and Maxell are cobalt formulations, not nearly as abrasive. Most Japanese decks are designed for TDK-SA. BASF was dirty tape and dropped oxides all over everything.
Everything is about calibration. The better the noise reduction is, the more critical calibration to that tape is. Listening carefully, you can easily hear the difference between tapes because the bias and level adjustments are different for record. For playback they should be on international standard (IEC for cassette).
Sendust is a different type of head. Great name, generic. More efficient, lower noise and slightly harder than permalloy. Permalloy is pretty good, Sendust was developed later. Ferrite just performs poorly, it is harder but doesn't cut it.
So whatever that machine was calibrated for would sound better than a "better tape" would. But calibrate it for the better tape and you would have lower noise, lower distortion and probably more even frequency response that went higher.
Everything is about calibration. The better the noise reduction is, the more critical calibration to that tape is. Listening carefully, you can easily hear the difference between tapes because the bias and level adjustments are different for record. For playback they should be on international standard (IEC for cassette).
Sendust is a different type of head. Great name, generic. More efficient, lower noise and slightly harder than permalloy. Permalloy is pretty good, Sendust was developed later. Ferrite just performs poorly, it is harder but doesn't cut it.
So whatever that machine was calibrated for would sound better than a "better tape" would. But calibrate it for the better tape and you would have lower noise, lower distortion and probably more even frequency response that went higher.
THE FULL PROCEDURE:
1. You play a 'certified' playback test tape of your IEC or NAB format & zero reference level. ( I always used MRL test tapes )
2. If the adjustments are available > You adjust: Height, Wrap, Zenith and Azimuth for optimal performance.
If playback heads are worn to any significant degree, you DON'T touch any of the above adjustments.
3. You adjust your playback Zero reference output & metering.
4. You adjust your playback frequency response using the 'spot frequencies' of your test tape.
* If HF spec. can't be achieved in one channel, you can add small capacitance across the head AND/OR playback level pot.
5. Re-check playback Zero reference.
6. Adjust your "bias traps" at test points for maximum NULL.
7. With your desired tape type in record mode, adjust for "peak bias" @ 1Khz.
8. Adjust HF record EQ to achieve flattest response.
9. If either channel is not flat, or out of spec. use UNDER or OVER biasing to correct.
*Use this 'interplay' of bias & HF eq to achieve the flattest frequency response.
10. Allways double-check your Rec/Play zero reference.
PS.
Using pink noise IS A WONDERFUL WAY to adjust things by ear
1. You play a 'certified' playback test tape of your IEC or NAB format & zero reference level. ( I always used MRL test tapes )
2. If the adjustments are available > You adjust: Height, Wrap, Zenith and Azimuth for optimal performance.
If playback heads are worn to any significant degree, you DON'T touch any of the above adjustments.
3. You adjust your playback Zero reference output & metering.
4. You adjust your playback frequency response using the 'spot frequencies' of your test tape.
* If HF spec. can't be achieved in one channel, you can add small capacitance across the head AND/OR playback level pot.
5. Re-check playback Zero reference.
6. Adjust your "bias traps" at test points for maximum NULL.
7. With your desired tape type in record mode, adjust for "peak bias" @ 1Khz.
8. Adjust HF record EQ to achieve flattest response.
9. If either channel is not flat, or out of spec. use UNDER or OVER biasing to correct.
*Use this 'interplay' of bias & HF eq to achieve the flattest frequency response.
10. Allways double-check your Rec/Play zero reference.
PS.
Using pink noise IS A WONDERFUL WAY to adjust things by ear
There has now been for years & years digital simulation/emulation of the sound of tape 'compression/saturation/distortion'.
Hi!
I looked the issue of the Sansui 8080DB and 9090DB dolby wiring and bypass a little last night, once some pins are numbered, and some pin numbers corrected, it becomes a rather simple task, even if the schematic and PCB layout are sometimes at odds with each other 🙂
Of course I may have made a mistake, but essentially I think my method is correct:
A picture is worth a thousand words (see pic), so this is my way to properly bypass the board with 4 jumper wires, and by moving the input from the F-2655 daughterboard to the F-2654 switch board, which is where it should have been anyway.
Unlike other mods, my bypass mod doesn't involve destroying the F-2655 board, that's simply left in place, ignored.
But:
As an aside however, this bypass is really just mimicking the 'Off' position on the Dolby selector switch, and in that setting I can't see anything but the dolby selector wafer switches (x3) and the tape monitor push switches (x2) - so if the signal is not getting through in the Off position it's either a broken ribbon or a dodgy switch.
I.e. The bypass simply eliminates 3x wafer switch contacts and the ribbon.
This then leads to my conclusion that the best way to fix this dolby circuit is to recap it, put a nice new flexible ribbon in it (potentially buying a swanky Silverflo vacuum desoldering station first....), and cleaning the switches - because if they, and the ribbon, are working, Off will bypass it - as designed.
😀
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Re. Dolby & DBX
In my roughly 2 years of transferring quarter inch master & copy-master tapes to DAT for archive purposes,
I found many interesting things regarding noise reduction systems.
It turned out that there are 3 kinds of DBX encoding. With DBX, given the correct decoder, things worked and sounded good.
However, with Dolby A, it was not so easy to get a good sounding transfer. Just setting the calibration tone did NOT always provide good sound.
The solution I found was to sometimes apply PRE-decoder EQ, > which is quite different to POST decoder EQ.
In my roughly 2 years of transferring quarter inch master & copy-master tapes to DAT for archive purposes,
I found many interesting things regarding noise reduction systems.
It turned out that there are 3 kinds of DBX encoding. With DBX, given the correct decoder, things worked and sounded good.
However, with Dolby A, it was not so easy to get a good sounding transfer. Just setting the calibration tone did NOT always provide good sound.
The solution I found was to sometimes apply PRE-decoder EQ, > which is quite different to POST decoder EQ.
Yes. BrAun used mainly GRUNDIG and PHILIPS speakers in their enclosures.
Grundig ? I don't know, but certainly... BrAun notably made "integrated turntables", like the Cockpit 250 that my Parents had (trashed for long by them, a crime 😡...). It was exactly this one below - also designed by Dieter Rams :
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That's true ! I'd be glad to find a little, protable True Pink Noise generator...
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Very interesting guy, some superb designs!
It seems he also did some designs for Grundig such as the Audiorama 4000 speakers..
... so this explains why the Braun and Grundig speakers had a 'family look' with the curved edges, recessed metal grill capture and overall design !
I remember B&O made some football shaped speakers a few years ago - I did demo them in a shop with Katie Melua's 'Lilac Wine'. Well, it was the first time I'd heard a speaker that made her seem flat, lifeless and ordinary.. so I suspect that despite the inherent issues of spheres, Dieter's sounds better 🙂
My remaining thought is: 'Where did all the creativity of the 1960s go?'.
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Some android apps have it! iPhone too I suspect.. 🙂
E.g:
https://play.google.com/store/apps/details?id=radonsoft.net.signalgen&hl=en-US
@Globulator writes:
"My remaining thought is: 'Where did all the creativity of the 1960s go?'."
Have had the same thought and decided that creativity is the result of a fine mind challenged to produce and those people are in AI these days.
What's also interesting is to read product reviews from that day. What a difference! Typically straightforward and direct.
And, btw, spend a great deal of time with Dolby units -- with Dolby B for listening playback and Dolby SR for recording machines (I use Otari ones) and have found that the Dolby NR units that still work are the ones with lots of ICs and they just don't sound very good. The Dolby PCBs in the Revox A77s are the best but they fail with bad caps and trimpots and are a nightmare to disassemble and troubleshoot.
Recently purchased an entire unit just to get the Dolby boards and, thankfully, they worked. The PCBs without ICs are markedly better sounding.
Dolby as a process gets lots of bad reviews and the company is to be criticized for not providing support any longer (at least the circuits and cassette parts would be appropriate). But it is, of course, NOT an EQ and can offer tremendous analog sound when properly calibrated. Dobly SR is a challenge to calibrate well but produces entirely noiseless results even at 15ips. At 30 ips it is golden.
"My remaining thought is: 'Where did all the creativity of the 1960s go?'."
Have had the same thought and decided that creativity is the result of a fine mind challenged to produce and those people are in AI these days.
What's also interesting is to read product reviews from that day. What a difference! Typically straightforward and direct.
And, btw, spend a great deal of time with Dolby units -- with Dolby B for listening playback and Dolby SR for recording machines (I use Otari ones) and have found that the Dolby NR units that still work are the ones with lots of ICs and they just don't sound very good. The Dolby PCBs in the Revox A77s are the best but they fail with bad caps and trimpots and are a nightmare to disassemble and troubleshoot.
Recently purchased an entire unit just to get the Dolby boards and, thankfully, they worked. The PCBs without ICs are markedly better sounding.
Dolby as a process gets lots of bad reviews and the company is to be criticized for not providing support any longer (at least the circuits and cassette parts would be appropriate). But it is, of course, NOT an EQ and can offer tremendous analog sound when properly calibrated. Dobly SR is a challenge to calibrate well but produces entirely noiseless results even at 15ips. At 30 ips it is golden.
One way is to repurpose an old portable 1/2 gig mp3 player no one wants anymore. Battery powered, it floats so there's no ground loops. You can get the Pink noise as a file off the net. You can also use an SD card player from ebay / alibaba that can drive a speaker directly. Handy when encountering an interesting speaker out in the wild; will quickly show what drivers are still operating.
I read, regarding the GM's initial stab at an electric car, that the engineer were told "This may be the only chance in your career to do something truly creative" i.e., fun. I suspect the job otherwise is to engineer 0.01 cent out of a door handle production cost, while minimizing structural integrity loss.
Hi Globulator,
I'll have a look later on, and it may be a great deal later on! lol!
You have the right idea. To be honest, you're further ahead to bypass the entire mess. The last one I repaired involved going back in a few times to repair top to bottom connections, and inter board connections. As soon as you disturb this mess, other things happen. Since no one uses outboard Dolby units anymore, the circuit is entirely pointless. FM Dolby broadcasts were very short lived, so the receiver based Dolby processors have no purpose.
Somewhere I remember the Dolby boards provided gain. I could be wrong, but I was sure they used a defeated Dolby board as a gain stage. If it doesn't provide gain - GREAT!!! That just makes life easier.
Wishing you luck!
I'll have a look later on, and it may be a great deal later on! lol!
You have the right idea. To be honest, you're further ahead to bypass the entire mess. The last one I repaired involved going back in a few times to repair top to bottom connections, and inter board connections. As soon as you disturb this mess, other things happen. Since no one uses outboard Dolby units anymore, the circuit is entirely pointless. FM Dolby broadcasts were very short lived, so the receiver based Dolby processors have no purpose.
Somewhere I remember the Dolby boards provided gain. I could be wrong, but I was sure they used a defeated Dolby board as a gain stage. If it doesn't provide gain - GREAT!!! That just makes life easier.
Wishing you luck!
Hi Mister Audio,
Yes, that's the basic procedure. I'm glad you noted that an established tape path means you cannot adjust or correct tape path like Azimuth. Three head Nakamichi decks can be adjusted after wear due to their head design. Those should be bang-on.
One very common issue is a worn capstan bearing. Check this first before anything as long as you have good tape tension. A badly worn bearing will cause the tape to run up against the guides towards the mechanism. You may see a feathered edge on the tape. If you do, the machine is done and you will destroy test tapes. It needs a new capstan bearing and most are unavailable. In fact, most were permanently installed in the mech chassis.
Yes, that's the basic procedure. I'm glad you noted that an established tape path means you cannot adjust or correct tape path like Azimuth. Three head Nakamichi decks can be adjusted after wear due to their head design. Those should be bang-on.
One very common issue is a worn capstan bearing. Check this first before anything as long as you have good tape tension. A badly worn bearing will cause the tape to run up against the guides towards the mechanism. You may see a feathered edge on the tape. If you do, the machine is done and you will destroy test tapes. It needs a new capstan bearing and most are unavailable. In fact, most were permanently installed in the mech chassis.
Check out the Radio Shack catalogs from the 1960s:
https://www.radioshackcatalogs.com/
The number of R2R decks is impressive. Those of us active then remember lusting after the Ampex ones and there was, in the air, a feeling that tape was the future. Sadly, the loading process did not pass the general cultural acceptance...
https://www.radioshackcatalogs.com/
The number of R2R decks is impressive. Those of us active then remember lusting after the Ampex ones and there was, in the air, a feeling that tape was the future. Sadly, the loading process did not pass the general cultural acceptance...
lol!
R-R tape machines were the only good option in the early 1970's even. Cassette tape was for dictation, 8-tracks sounded better.
Recordable CDs killed everything, even DAT tapes. CDs killed the turntable market. Then memory killed all of that, and streaming.
One thing that all tape formats required was maintenance and they wore. Same for records. The public generally wants cheap and easy, quality be damned. ... and here we are.
R-R tape machines were the only good option in the early 1970's even. Cassette tape was for dictation, 8-tracks sounded better.
Recordable CDs killed everything, even DAT tapes. CDs killed the turntable market. Then memory killed all of that, and streaming.
One thing that all tape formats required was maintenance and they wore. Same for records. The public generally wants cheap and easy, quality be damned. ... and here we are.
I am often ashamed on how far norms due to morons and their trials kill creativity, simplicity, and finally efficiency...
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