"CCD" not "BBD" in Boss DM-1 Delay

[Vsat]

Anyone know what delay chip was used on the Boss DM-1 (from 1978)? I have been told it was a CCD instead of a BBD.... the Marshall Time Modulator apparently also used CCD's.
Mike

[toneman]

a CCD  "ChargeCoupledDevice"
and a BBD  "BucketBrigadeDelay"
CCDs are used on digital cameras, and,
actually are memory devices.  When U focus a
light, thru a lens, and scan the "memory",
the bits are representative of the amount of
light on each pixel.  BYTE magazine, long time
ago, ran an article on making a framegrabber
using a dynamic ram that U pulled the top off of.
wierd or what.
Recticon, the makers of the "SAD" chips, "SerialAnalogDelay"
originally advertized them to delay video timing signals.
Don't know what was in the DM-1, but if it was a "delay"
it *has* to B a SerialAnalogDelay, cause they didn't have
cheap digitals back then.
Anyone else know??
afn
tone

[ExpAnonColin]

Read read read...

http://www.bossus.com/bugonline/fretbuzz_retro.asp

From a retailer...

1978
Boss
DM-1 Delay Machine
Rare rare rare analog delay w/coveted CCD chips. You need this!
$450

That would be interesting to look at.

Wikipedia: http://en.wikipedia.org/wiki/Charge-coupled_device

-Colin

[Peter Snowberg]

CCDs are based on a shift register like structure where each horizontal line is shifted into a buffer and then out serially.

I could easily see some early CCD having a test input that would allow injecting a signal.

If the resolution is typical of early devices and we assume high quality with 640x525 resolution, that's roughly 336K. I'm assuming that it's really lower like 512x512 which would be more like 256K.

I wonder about the dynamic range. I'll bet it's not super but I would assume that you would get at least 7 bits out of it.

Forget about finding a replacement CCD.

It was a really cleaver way to get delay at that early time. I wonder if the chips were manufacturing defects that wouldn't work perfectly for image capture but have their analog shift registers in tact.

There are better ways to delay a signal these days.

[rocket]

AFAIK both terms were used interchangeably in former days (before "CCD" was used more specifically for camere chips).

[george]

You need this!
$450

of course I do.  Pity if I had the CE-1 as well I'd only be able to fit two pedals on my pedalboard.

Note Boss only cares about it's long discontinued products if they think it will help sell one of their new (read crappy) ones.

from what I'm reading here CCD's are basically BBD's only BBD's need a clock to drive them.

[Peter Snowberg]

CCD image sensors need clocks too. Instead of a single two phase clock a BBD requires, they need a clock for horizontal shifting and a clock for vertical shifting derrived from the horizontal clock divided by the number of pixels per row.

[Vsat]

If you google on CCD audio delay there was a discussion on a list a few yrs back where someone posted that he built a delay unit using a "TCD102" CCD chip - an early linear CCD array - says that 300 mS can be achieved, but that he likes to keep it under 150 mS as it gets noisier with the long delays. Also mentioned MN3649 and uPD3573D.

Apparently these are very temperature sensitive - noise doubles for every 8 degree Centigrade temperature rise... use a small thermoelectric cooling module to reduce noise (this could also be done with BBDs - they are temperature sensitive too... but would take a LOT of current!)
Regards, Mike

[analogmike]

AFAIK both terms were used interchangeably in former days (before "CCD" was used more specifically for camere chips).

That seems correct to me.

[Mark Hammer]

I would concur.  This seems like one of those things like "tremolo" and "vibrato", where despite having distinct meanings two terms are batted around in the "untutored" public forum as if equivalent, until at some point they are clearly distinguished from each other.  The SAD-1024 *was* spec'd (and appnoted!) for video applications, and I do recall hearing it described as a charge-coupled device....maybe even on Reticon's own datasheets.  It was also the preferred chip for delays beyond the chorus range until the MN3005 and SAD4096 came around.  My guess is that the DM-1 was similar to the early Memory Man (which also used SAD1024's untila MN3005 could replace them).

[Jason M.]

Anyone know what delay chip was used on the Boss DM-1 (from 1978)? I have been told it was a CCD instead of a BBD.... the Marshall Time Modulator apparently also used CCD's.
Mike

My DM-1 has a Reticon R5101 in it, like one of the versions of the MXR Analog Delay.

From "The Boss Book," on the DM-1:

"When this machine appeared, Roland had already established a name for itself with the popular delay machines in the Space Echo Series (which used a tape echo), but the DM-1 was an analog stereo delay that debuted under the Boss brand. In trying to squeeze out just a little more delay time, Boss engineers used a CCD (an imaging component used today to capture images in video cameras) instead of a BBD as the delay element at the heart of the delay circuit."

My guess is that CCD's just had more stages than BBD's.

The DM-1 sounds good. Not unlike the Ross Stereo Analog Delay, which uses three SAD1024's.

[Vsat]

Thanks a lot Jason - not as mysterious as I was expecting...!
My 1983 Reticon book has the R5106,7,8 but does not mention the R5101.
Regards, Mike

[george]

CCD image sensors need clocks too. Instead of a single two phase clock a BBD requires, they need a clock for horizontal shifting and a clock for vertical shifting derrived from the horizontal clock divided by the number of pixels per row.

thanks Peter.

so the difference is not so much in sound quality or any "voodoo", just that they had more stages (and therefore more delay) than any BBD available at the time?

I hope I didn't cause any offence to Colin, I just had to laugh at the hype some  retailers come up with ...

[Jason M.]

Mike,

I knew I had seen some Reticon specs somewhere...

Your buddy Mark Hammer has it in the BBDementia.zip file at hammer.ampage.org, in the Reticon zip file.

It explains the differences btw BBD and CCD.

[ExpAnonColin]

I hope I didn't cause any offence to Colin, I just had to laugh at the hype some  retailers come up with ...

No offense whatsoever, I was just posting some resources.

-Colin