Topic: Oade modSBM-1 discussion

[Brian Skalinder]

there are many a/d converters that are capable of 24 bit, although none as small as the SBM-1.

Just for clarity's sake, since one could interpret this as indicating the SBM-1 outputs 24-bits:  the SBM-1 does not output 24-bits.

[Ray76]

there are many a/d converters that are capable of 24 bit, although none as small as the SBM-1.

Just for clarity's sake, since one could interpret this as indicating the SBM-1 outputs 24-bits:  the SBM-1 does not output 24-bits.

Good point Skalinder. The oades DID a mod that allowed an output of 20 bits, which of course was truncated down by the DATS to 16. However, the A/D chip that Doug used to do the actual mod is no longer on the Market, neither in SONY America Or Europe.

Teddy

[detroit lightning]

ahh...it's starting to come together.

thank you all for the info

can't wait until some reviews start coming in on this thing...

[Ray76]

ahh...it's starting to come together.

thank you all for the info

can't wait until some reviews start coming in on this thing...

no problem buddy.

[Brian Skalinder]

Good point Skalinder. The oades DID a mod that allowed an output of 20 bits, which of course was truncated down by the DATS to 16. However, the A/D chip that Doug used to do the actual mod is no longer on the Market, neither in SONY America Or Europe.

Huh...never heard about that one - which mod was that?  I take it not one of the commonly available ones he had listed on the Oade site while they were still performing SBM-1 mods.  Interesting...

[Ray76]

Oade called their line stage mod a "24 bit mod", but it doesn't transmit 24 bits. It produces a 24 bit signal, then dithers down to 20 bit, which DAT decks then take further down to 16.
(thanks Nick)
A couple of folks on the oade site talk about having 24 bit SBM1s....

[Brian Skalinder]

Oade called their line stage mod a "24 bit mod", but it doesn't transmit 24 bits. It produces a 24 bit signal, then dithers down to 20 bit, which DAT decks then take further down to 16.

Per the manual, the stock SBM-1 ADC creates a 24-bit signal and then employs the SBM process to dither down to 16-bit for output.  My understanding of the Oade "line-stage" mod is that it upgraded analog components only and did NOT change the ADC, and therefore, it, too, only outputs 16-bits, not 20.

[Brian Skalinder]

Oade called their line stage mod a "24 bit mod", but it doesn't transmit 24 bits. It produces a 24 bit signal, then dithers down to 20 bit, which DAT decks then take further down to 16.

Per the manual, the stock SBM-1 ADC creates a 24-bit signal and then employs the SBM process to dither down to 16-bit for output. My understanding of the Oade "line-stage" mod is that it upgraded analog components only and did NOT change the ADC, and therefore, it, too, only outputs 16-bits, not 20.

And...perhaps the manual isn't entirely clear, as Mic D referenced this info from the Oade Bros old board...which in turn was sourced from a Sony rep:

Snagged from the oade archives...

This was how the Sony technical support rep I just got off the phone
with explains the SBM A/D used in all their products carrying that
identifier in simple terms. This is using simplified explanations,
so computer geeks, please overlook the obvious generalizations.

" The SBM initially quantitizes the analog signal into 24bit data and
then through a noise shaping filter which is the core of the SBM
process. First it analyzes the entire waveform and identifies bytes
of noise information it finds in the audible bandwidth that it
captures until it reaches 4 bits worth of this information. This 4
bits of information is then cut out completely. The remaining 20
bits of data are then reintegrated, or dithered, into the 16 bit
word length."

But the bottom line, I believe, is that Oade Bros did NOT modify the ADC at all - only the line-in analog stage.

[Ray76]

No they actually did, replaced the stock SBM-1 ADC with a different(though still sony) chip. Asked Doug himself a while back. wouldnt give me the name of the chip of course...At the time he was still doing partial mods to the SBMs IE upgrading the Opamps in the signal path, but not complete mods like he did before involving upgrading the adc..

As to what the replacement of the chip did for word length, etc..I have no idea. I do that he did in fact replace the ADC when the parts were still available.

He said he had one more of that particular chip in, but had to use it for repairs or something...You know how Doug is..ever cryptic...

[Brian Skalinder]

No they actually did, replaced the stock SBM-1 ADC with a different(though still sony) chip. Asked Doug himself a while back. wouldnt give me the name of the chip of course...At the time he was still doing partial mods to the SBMs IE upgrading the Opamps in the signal path, but not complete mods like he did before involving upgrading the adc..

As to what the replacement of the chip did for word length, etc..I have no idea. I do that he did in fact replace the ADC when the parts were still available.

He said he had one more of that particular chip in, but had to use it for repairs or something...You know how Doug is..ever cryptic...

It wouldn't surprise me if Doug tinkered around with swapping out ADC chips in a unit or two for kicks.  But for production, it would surprise me.  So...just to make sure I'm clear:  you're suggesting the commonly available line-stage modSBM-1 replaced the ADC chip?

As in the one that used to be described on the Oade website as The fourth [mod] is a complete line stage rebuild which dramatically improves the sense of depth and detail in the SBM-1?

As in the same mods he offered as the one you're selling in the Yard Sale?

[Ray76]

No they actually did, replaced the stock SBM-1 ADC with a different(though still sony) chip.

It wouldn't surprise me if Doug tinkered around with swapping out ADC chips in a unit or two for kicks.  But for production, it would surprise me.  So...just to make sure I'm clear:  you're suggesting the commonly available line-stage modSBM-1 replaced the ADC chip?

As in the one that used to be described on the Oade website as The fourth [mod] is a complete line stage rebuild which dramatically improves the sense of depth and detail in the SBM-1?

As in the same mods he offered as the one you're selling in the Yard Sale?

No, I think that one is what folks refer to as the "24 Bit mod" over on oade...I dont know much about it though. The one I have is the line stage rebuild and coax mod, which, to my knowledge , dont require messing with the ADC at all. Details from Doug were sketchy at best...But when I asked him what could be done to SBM1s , he said he could partially mod units(line stage upgrade and coax) but that the full gamut couldnt be done due to the inavailability of the ADC chip he used......Mine is only a wmod/ signal path upgrade..
If someone has clarification, id be glad to hear it...

[dmonterisi]

fyi, here is google's cached version of the old Oade page describing the 4 upgrades doug offered to the mod sbm1.  NB that none of them references replacing the a>d converter.  i've attached a pdf of the page.

http://66.102.7.104/search?q=cache:-hoZ2JpKwq0J:www.oade.com/audiocenter/upgradesbm1.html+oade+sony+sbm-1+upgrades&hl=en

The Sony SBM-1 , is a fine convertor. It is our first choice for in the field A/D conversion. We offer four performance upgrades for this unit.
The first involves replacing the mic preamp circuit. This upgrade is similar to our D7/8 mic input upgrade. It allows for a higher input level before overload and lowers the noise floor, producing a cleaner recording with less hiss. We charge $125.00 for this service.

The second is a Digital I/O upgrade which provides a coax digital output cable. We use the 7 pin cable end to provide a passive 7 pin to Coax "y" adapter for use with the D3/7/8 or in the second Digital I/O port on the SBM-1. The end result is a sturdy 7 pin to RCA "y" Digi I/O cable and a standard coax output on the SBM-1 all for only $150.00.

The third is a line input upgrade which increases the line input gain stage to allow for line in recording with mics that have SLIGHTLY less output than needed for line level input. This upgrade only increases gain. We charge $50.00 for this one.

The fourth is a complete line stage rebuild which dramatically improves the sense of depth and detail in the SBM-1. An additional 6 dB of gain is available at your request, we recommend this only if you are NOT using an external preamp. We disable the mic preamp for this upgrade as the stock chips use too much power. We charge $250.00 for this service. We can do this upgrade with the Mic Input upgrade or either of the first two. There is no discount for combining upgrades.

[dmonterisi]

from this thread

http://www.oade.com/cgi-bin/miva?Forum/technology/showmsg.mv+message=6166

"The line stage mod simply changes the equalization to provide a
warmer sound with cetain mics."
 The line stage rebuild actually improves detail dramatically by
improving the detail in the analog signal presented to the A/D chip.
This is not EQ or any other form of coloration, it is simply an
audible improvement in signal clarity. The SBM-1's AD converter
does sound warm and natural, like most Sony studio gear. The bit
mapping done by the Sony 45 bit DSP chips does not color the
signal, it reduces low level distortion with SBM dither and this
allows 16 bit data to resolve nearly as much detail as 20 bit data.

 Sorry, I am so slammed with work, I do not have time to go in to
more detail, Studio Geek's post along with this one , I hope, will
clear things up...peace...>Doug

this is studio_geek's post referenced by Doug:

http://www.oade.com/cgi-bin/miva?Forum/technology/showmsg.mv+message=6142

 Most DAT decks only record 16 bits, but a lot of 16 bit AD
converters are 24 bit capable. The SBM-1 uses a 24 bit AD chip to
provide data for the 24 bit DSP chip. This DSP chip applies SBM to
the 24 bit data, then outputs 16 bit data that sounds like 20 to 24
bit recordings. Some tapers call Doug's SBM-1 upgrade a 24 bit mod,
but the SBM can only output 16 bit data, maybe it's near 24 bit
sound is why.  I asked Doug about making the SBM-1 output 24 bit
data and he said he did not do that, I doubt any 24 bit output
SBM-1's exist. The line stage rebuild disable the stock mic preamps,
due to power restrictions, but you can run the modified SBM-1's
internal mic preamps, if you also have the mic preamp mod done.

[Brian Skalinder]

No, I think that one is what folks refer to as the "24 Bit mod" over on oade...I dont know much about it though. The one I have is the line stage rebuild and coax mod, which, to my knowledge , dont require messing with the ADC at all. Details from Doug were sketchy at best...But when I asked him what could be done to SBM1s , he said he could partially mod units(line stage upgrade and coax) but that the full gamut couldnt be done due to the inavailability of the ADC chip he used......Mine is only a wmod/ signal path upgrade..
If someone has clarification, id be glad to hear it...

We've been through this before.  The "24-bit" mod IS the line stage mod.  Just a misnomer due to the labelling of the box.  See this thread and note the absence of any indication that Doug mods the ADC chip in his cached pages describing his SBM-1 mods.

[Ray76]

fyi, here is google's cached version of the old Oade page describing the 4 upgrades doug offered to the mod sbm1.  NB that none of them references replacing the a>d converter.  i've attached a pdf of the page.

http://66.102.7.104/search?q=cache:-hoZ2JpKwq0J:www.oade.com/audiocenter/upgradesbm1.html+oade+sony+sbm-1+upgrades&hl=en

The Sony SBM-1 , is a fine convertor. It is our first choice for in the field A/D conversion. We offer four performance upgrades for this unit.
The first involves replacing the mic preamp circuit. This upgrade is similar to our D7/8 mic input upgrade. It allows for a higher input level before overload and lowers the noise floor, producing a cleaner recording with less hiss. We charge $125.00 for this service.

The second is a Digital I/O upgrade which provides a coax digital output cable. We use the 7 pin cable end to provide a passive 7 pin to Coax "y" adapter for use with the D3/7/8 or in the second Digital I/O port on the SBM-1. The end result is a sturdy 7 pin to RCA "y" Digi I/O cable and a standard coax output on the SBM-1 all for only $150.00.

The third is a line input upgrade which increases the line input gain stage to allow for line in recording with mics that have SLIGHTLY less output than needed for line level input. This upgrade only increases gain. We charge $50.00 for this one.

The fourth is a complete line stage rebuild which dramatically improves the sense of depth and detail in the SBM-1. An additional 6 dB of gain is available at your request, we recommend this only if you are NOT using an external preamp. We disable the mic preamp for this upgrade as the stock chips use too much power. We charge $250.00 for this service. We can do this upgrade with the Mic Input upgrade or either of the first two. There is no discount for combining upgrades.

Thats good info Damon,. thanks. I have no idea what he is talking about then...He clearly mentioned "replacing the stock ADC with a different version  that wasnt available anymore"
and that due to that problem he would do a line stage rebuild/upgrade but thats all he could do.
I had no idea what other options were out there so I said, ok....hmm....This is interesting..