Teac Model 5B Mixing Console Tour

sweetbeats

Reel deep thoughts...
I recently picked up a Teac Model 5B console for the purpose of scavenging some parts for my Tascam prototype 12x8 console...I've always dismissed these older Teac consoles...I'm sure this will be very old news for many here, but I somehow just totally missed these consoles (at least the Model 5), and it has some hidden gems...I'm a bit taken aback actually.

The modular design, materials used, PCB layouts, inductor eq, simple signal path...and a pretty decent feature set...I dunno...I guess I'm just surprised I've missed this all these years.

Here's a YouTube video I uploaded where I go on and on about it: :o

https://youtu.be/qFp_6NSIuoo

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I am pretty surprised at the build quality... makes me change what I always thought about some of those mixers.

Pretty impressive build quality. No idea on sonics - but clearly someone was thinking long term.
 
I had a Model 5 as my first 'real' mixer. It exhibited background noise I could not tolerate, and was replaced in short order with a M308B.
I concur however that the construction of the Model 5 was really nice. Built like a tank.
 
I mixed all the albums in my signature link on a Model 5 (and recorded many of them through one). I went through a number of other mixers (some costing quite a bit more), but never found as appropriate a sound/vibe as the Model 5. This may sound like a crude comparison, but I would describe their sound as a cross between a real '60s-'70s record and a Portastudio!
 
I had a Model 5 as my first 'real' mixer. It exhibited background noise I could not tolerate, and was replaced in short order with a M308B.
I concur however that the construction of the Model 5 was really nice. Built like a tank.

Yeah I've read a bit of feedback about the noise floor in the Model 5. The 5B should be improved in this area because of the significantly lower noise spec on the (at the time cutting edge) 4559 opamps as opposed to the Model 5 and 5A which were fitted with 4558 opamps. I've also already identified some cheap and simple changes to the power supply that should help to lower the noise floor. There's no reason this aspect can't be well within accepted norms on the 5B.

And the build design and quality are just a real mind-bender...these are the most carefully designed PCB layouts I've ever run across in a mixer...and each PCB is mounted to each module frame (which in and of itself is comprised of a full height and depth solid piece of heavy-gauge high-quality yellow zinc plated steel) on metal stand-offs...and the card-edge connector is a separately mounted PCB so there is no possible stress that can be transferred to the main PCB on each module when the module is being removed or installed...The wiring is so neatly done...the module assemblies are like an electronics work of art...I understand the mixer has some deficits or challenges sonically when compared to modern offerings (and one person's definition of deficits may be another person's definition of desires...), but there is no reason that can't be improved, and with relatively little effort and expense since the signal path is relatively simple...and the physical design and construction is just really under-rated...I didn't expect this.
 
Great video, thanks for sharing! You have a great way of describing gear that's both informative and respectful. I enjoyed watching. :)
 
As I recall, the differences between the original Model 5 and 5B were the chips used and the color of the knobs. They went from 5538's to the slightly faster 5539's.
 
I enjoyed the tour..... I really do like the modular design. Your explanations of the parts and processes of those parts really help a novice like me begin to understand more and more about these things.
 
I have his 2 part M520 mixer tour video stored on both my recording computer and my laptop. :D
 
As I recall, the differences between the original Model 5 and 5B were the chips used and the color of the knobs. They went from 5538's to the slightly faster 5539's.

Yes, but the chips were 4558 and 4559 respectively for the 5/5A vs 5B. They are similar, but the 4559 was faster and was a lower noise part. Otherwise yes the 5A and 5B were identical except for the knobs used. There were actually quite a lot of differences between the 5 and the 5A...completely separate schematics for a number of the boards...significant differences between the power supplies too. The 5A and 5B are much more alike than the 5 and 5A...but they all share the same chassis construction...same as the M-35 that succeeded the 5 series.
 
Yes, very nicely made. On the noise front the RC4559s could be swapped for LM4562s which are quieter even than the NE5532 and have a slightly better load/distortion performance.

"Faster" is a bit of a red fish in audio circles. A slew rate above 2V/muSec is entirely adequate for any "real life" audio signals* . There have not been any audio chips made since the days of the 741 that were a problem in this respect!

The current consumption of the 4562 ref the 4559 needs checking if a mass swap out is envisaged. What are the supply rails anyway? If + and - 18V it might be worth changing that to 17V x2 as this gives vastly better chip reliability according to the source below. The loss of headroom is an inconsequential dB or so.

*Douglas Self. Small Signal Audio Design.

Dave.
 
Yes, very nicely made. On the noise front the RC4559s could be swapped for LM4562s which are quieter even than the NE5532 and have a slightly better load/distortion performance.

"Faster" is a bit of a red fish in audio circles. A slew rate above 2V/muSec is entirely adequate for any "real life" audio signals* . There have not been any audio chips made since the days of the 741 that were a problem in this respect!

The current consumption of the 4562 ref the 4559 needs checking if a mass swap out is envisaged. What are the supply rails anyway? If + and - 18V it might be worth changing that to 17V x2 as this gives vastly better chip reliability according to the source below. The loss of headroom is an inconsequential dB or so.

*Douglas Self. Small Signal Audio Design.

Dave.

The audio power rails are +/-15V.

And yeah I was really just talking about the slew rate as a statement of fact, not so much that it's "better". The lower noise of the 4559 vs the 4558 is likely the most noticeable change IMO.
 
Yes, but the chips were 4558 and 4559 respectively for the 5/5A vs 5B. They are similar, but the 4559 was faster and was a lower noise part. Otherwise yes the 5A and 5B were identical except for the knobs used. There were actually quite a lot of differences between the 5 and the 5A...completely separate schematics for a number of the boards...significant differences between the power supplies too. The 5A and 5B are much more alike than the 5 and 5A...but they all share the same chassis construction...same as the M-35 that succeeded the 5 series.

Correct.
 
Ah well, 15V drops the headroom by about 2dB compared to 18V but the chips will last forever!
As this is pretty well controlled "home" recording you can ensure things never get close to overload.

I mentioned slew rate only because many people have got hung up on it in the past. One of those fashions that come and go in audio circles!

Thought occurs that should you need a really low noise input or two there is always the Cloudlifters and Fetheads?

Dave.
 
Way back when I had the Model three...I use to lust after the 5, plus they had the extender channels fro that, if I recall...and I was really looking at that as my next step up...but then I kinda hit a lull in my recording (I moved, got sidetracked with other things for a couple of years)...then when I finally got back to it, I realized that technology had taken a few more steps...and eventually I ended up with the 3500 board.

Just looking at your 5...brings back a lot of great memories from my early days of home recording. :)

Are you planning to use it in a new recording rig...or just doing a refurb/resell...?

Oh yeah...nice job with the video. :thumbs up:
 
Ah well, 15V drops the headroom by about 2dB compared to 18V but the chips will last forever!
As this is pretty well controlled "home" recording you can ensure things never get close to overload.

I mentioned slew rate only because many people have got hung up on it in the past. One of those fashions that come and go in audio circles!

Thought occurs that should you need a really low noise input or two there is always the Cloudlifters and Fetheads?

Dave.

Cloudlifter is a wonderful thing.
 
Way back when I had the Model three...I use to lust after the 5, plus they had the extender channels fro that, if I recall...and I was really looking at that as my next step up...but then I kinda hit a lull in my recording (I moved, got sidetracked with other things for a couple of years)...then when I finally got back to it, I realized that technology had taken a few more steps...and eventually I ended up with the 3500 board.

Just looking at your 5...brings back a lot of great memories from my early days of home recording. :)

Are you planning to use it in a new recording rig...or just doing a refurb/resell...?

Oh yeah...nice job with the video. :thumbs up:

Cool anecdote. :)

You know I don't really know what I'm going to do with the 5B. It was originally going to be a "scavenge the color knob caps, test/repair, and try and flip it for what I paid for it" kind of deal, but I'm so enamoured with the build design/quality it's probably gonna stick around...and I'll probably want to see how it cleans up...replace the burned out meter lamps...if I like the sound of it at all I'll likely want to see what happens with a recap of a couple channels using some 105C audio-grade caps, maybe replace the feedback resistors with MF parts, and maybe some conservative opamps changes...at least socket a couple channels and try some different parts...and I've got an email out to Jensen to see if they know what in their lineup is an equivalent drop in replacement for the mic trafo...and recap and mod the power supply for lower noise. That's what I'm kind of thinking right now. They just did such a good job with the design and the build, and the signal path is so simple...

I wish the faders were long throw. The factory parts are way below par compared to the rest of the build and parts selection. Might try upgrading a couple of those with 60mm K packs or something just to see. They'll fit.

For now it's going to sit on the bench.
 
Don't know what you have in the way of test gear Sweets' but I would like to see some speccs before you tear into that mixer!

If it is not considered heresy here, you can check noise and frequency response with a computer and modest soundcard/ AI.

The book I mentioned give some good advice re cleaning up a power supply.

Dave.
 
I've been going through the 5B this last week. Need some $$$ in my pocket and some space on the workbench. I repaired a broken fader, broken output level switch, replaced the meter lamps, repaired the hinged wrist-rest, installed a bunch of missing screws responsible for structural integrity of the frame, and am doing a quick internal and external cleaning, applying DeoxIT to all the open switch contacts and replacing loose knobs.

I wish my prototype Tascam mixer (the "M-__") was constructed like this mixer. It's really impressive. There was an attention to detail and level of physical engineering design that dropped away a bit with the M-500 mixers and then again with the M-300 series. I'm not knocking Teac/Tascam or those product lines. I understand why they did it. They were focusing on a price point, and they were adding many, many useful features with those later product lines and there had to be compromises...and I've consistently stated they were very smart in their choices they made to achieve those compromises. But they really had something going on with their mixers with the Model 5, Model 15, M-35 and M-16 products. And then it shifted. I wish the physical design carried forward as the electronic feature set advanced. If there was an 8-buss 16 channel M-300 mixer built like the Model 5/Model 15/M-35/M-16...yowza that would have been cool. My M-__ looks chintzy under the skin compared to the 5.

Some pics...

Working on the meter lamps:

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Annnnnd all done...who doesn't like the incadescant glow of a set of analog VU meters. And the larger meters are a higher quality unit than the M-500 or M-300 mixers. I don't know if the HF ballistics are any better, but they are physically higher quality...and the bezel frames in the meter panel aren't plastic...cast aluminum:

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And look...the faux wood side panels...they have the laminate on the inside as well as the outside surface...you never see the inside surface as it is mated to the aluminum plate side panel:

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And here is that aluminum plate side panel...nicely formed and machined:

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And the backplane is all point-to-point wired to the motherboard...no worries about solder joint failures with PCB-mounted RCA jack clusters:

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And I really think the hinged wrist-rest is cool...remove two screws, the panel flips down giving clear access to remove one screw each for each module...remove a screw and unplug and lift out the module...and the card edge connectors are all the same high-quality Amphenol stuff companies like Ampex used for decades:

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And the modules themselves...! I know I covered this in my video tour earlier in this thread, but look at the attention to detail with the wiring and the component layout on the board...somebody cared about how this *looked* in addition to using good quality parts and (at the time) leading-edge active components:

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And yes the boards are phenolic instead of glass fiber, but it's some of the better quality resin boards I've worked with *and they are all screw-mounted to full-length high-quality yellow zinc plated steel panels!* This affords unmatched structural integrity AND module-to-module RF shielding!

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And the card edge connector on the module is a separate board from the component board...no stress on the component board when removing or installing modules...and it's all quality point-to-point wired and mounted with screws and nuts:

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And this is a minor detail, but look even at the labels on the modules...each module is labeled with a suffix number as to the module's slot placement from the factory...this is an inconsequential detail, but a detail to which somebody paid attention at the factory...it just tells me the depth of pride Teac had in this product. No...they don't make stuff like this anymore and that shift accurred within just a few years of the era of these Teac mixers...ended with the M-35 and M-16:

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