Origin of the Ibanez TS-808 Tubescreamer?

All about modern commercial stompbox circuits from Electro Harmonix over MXR, Boss and Ibanez into the nineties.
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POTL
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Post by POTL »

The Screamer has input and output buffers based on transistors
In modern distortion pedals buffers are generally not used, all of a sudden it dawned on me that you can opt out of these buffers.
As we know from the theory of the buffers have a gain coefficient equal to one, and therefore does not amplify the signal, so they do not make changes to the sound.
For myself, I made two assumptions:
1) They change the input and output impedance
2) This is the inheritance of the buffered bypass
The article anatomy Screamer I read that the input buffer improves work with wah pedals, but because the rest of the distortion pedal with no buffer at the entrance of great friends with wah pedals.
I would like to ask experienced people that will remove if bhodnoy and output buffer, what are the pros and cons I get.
I know that there is a scheme called son of Screamer, but I had never been heard live and was not able to compare with the original

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Post by phatt »

If you HATE hiss,fizz,humm,buzz. Then use the buffered input :thumbsup
Phil.

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Post by Dirk_Hendrik »

What Phil says above.

Other than that, stating "modern" distortion pedals do nut use buffers is not completely the case. Many manufacturers add buffers to ensure their pedals match other devices in the signal chain. For example the other pedals they make. Many other manufacturers went for "toan" and discarded (if they ever thought about it in the first place) the buffers. By doing so they also discarded the thought that multiple pedals match together. Result is a teriffic sounding pedal straight into the pedal builders amplifier and endless discussions online how other peoples amps or setup "do not like" this pedal.

I recently did a DFM project where the circuits (accompanied by a prototype) were "designed" by other "designers" (Most were adaptions of known themes) and my task was to get the designs ready for CE and FCC testing, as well as to ensure they were sonically as close to the original example as possible. Testing these pedals stand alone was no problem. Problems did arise when they were combined in the form of hum, osillations, noise pickup) Result is that eventually, while the pedals were True Bypass, I did, in many cases, redesign the buffers back into the pedals. Problems cured.

So, are buffers inherited from buffered bypass? I'd say no. They're inherited from a well thought over design approach where, because the end application is unknown, the design is made to match the worst case.
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Post by phatt »

Dirk_Hendrik wrote:What Phil says above.

Other than that, stating "modern" distortion pedals do nut use buffers is not completely the case. Many manufacturers add buffers to ensure their pedals match other devices in the signal chain. For example the other pedals they make. Many other manufacturers went for "toan" and discarded (if they ever thought about it in the first place) the buffers. By doing so they also discarded the thought that multiple pedals match together. Result is a teriffic sounding pedal straight into the pedal builders amplifier and endless discussions online how other peoples amps or setup "do not like" this pedal.

I recently did a DFM project where the circuits (accompanied by a prototype) were "designed" by other "designers" (Most were adaptions of known themes) and my task was to get the designs ready for CE and FCC testing, as well as to ensure they were sonically as close to the original example as possible. Testing these pedals stand alone was no problem. Problems did arise when they were combined in the form of hum, osillations, noise pickup) Result is that eventually, while the pedals were True Bypass, I did, in many cases, redesign the buffers back into the pedals. Problems cured.

So, are buffers inherited from buffered bypass? I'd say no. They're inherited from a well thought over design approach where, because the end application is unknown, the design is made to match the worst case.
Thanks Dirk,,Perfect Answer :thumbsup :thumbsup :thumbsup ***Gold Plate that one and put it up as a must read for ALL beginners ***

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Post by BJF »

Hi there,

As i recall Ibanez/Maxon had in the mid 70’s an orange pedal called Overdrive, while that was basically a Big Muff, and then a green pedal called Overdrive II that was version of MXR Distortion + albeit the OD II had after the distortion a boost cut Treble control the type you’d see in graphic eq’s. Both of those were true bypass with mechanical switch
By the late 70’s BOSS came out with a line and had ”Silent Switching” that was patented and OD-1 that was made with a quad OP and later changed for lower noise by transitorizing the buffers and using a lower noise dual OP for the main processing. BOSS in the OD-1 used asymmetric clipping in the feedback loop and patented that as asymmetric clipping. Shortly after that Ibanez/Maxon brought out Tube Screamer in order to compete with the OD1 and used the basis of ODII while they positioned the clipping diodes in the feedback loop but in a symmetric fashion since BOSS had the patent for asymmetric diodes in the feedback loop. Shortly after also most pedals came with silent switching although called something different as BOSS had the patent- actually even MXR tried to compete with their Command series…

Silent switching has done by timing switching of J-Fets and so switching noises and humps could be avoided while in order to use these J-Fet switches both input and output needed to be buffered and the lowest noise buffers at the time would be realized with discrete transistors also at great economy.
An anomali with these transistor buffers made as Emitter Followers is that Voltage gain is always below 1 times and while that has a positive effect on noise levels there is a voltage loss…at the time few would use more than two pedals and so such a loss would be ignorable...


Yes I had one of those ODII’s and later on a rainy day modified that to a Tube screamer for a poor guitarist that needed one-there were just a few minor changes …while that just contained the basic OD circuit and true bypass.


BOSS also brought out an orange distortion box and patented the combination of the words orange+ distortion and with the DS-1 a lower noise sibling of the Big Muff came about and that by using a low noise transistor and a low noise recording IC and in that making the first heavy distortion pedal.

So in my book OD-1 came first and the TS after in order to compete.

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BJ
BJF Electronics
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Post by POTL »

today designed distortion based on Marshall Guvnor and sought inspiration in the search for a better EQ (original or taken from Mi Audio Crunch Box do not like), in general, I looked at a lot of schemes and realized that the pedals overdrive or distortion buffers are present only in Screamer/SD1 style pedals, even in light overdrive King(Prince) of tone does not.
On this and question the wisdom of having.
My favorite clone Screamer / SD1 MXR Custom Badass Overdrive output buffer is completely removed for some reason.

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Post by Dirk_Hendrik »

Thanks for the story Bjorn. It reminds me I was planning to do more investigation on Boss and Roland patents from that time. However I have to corrrect you on the "true bypass" of the OD2 and the OD850 (Early version). They both have a SPDT switch that switches the to the input or the effect output. The input jack remains connected to the FX circuit at all time. Pretty much in the fashion of that time.
Sorry. Plain out of planes.

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Post by BJF »

Hi,

Yes Dirk, you are most right, single pole switching was the thing of the day then. So yes these Ibanez/Maxon definitely had the single pole switching.I guess it slipped my mind since I changed the switching to true bypass on the OD II I mentioned above and I actually had that unit in for service not long ago from a broken input jack.
So you are absolutely ,Dirk, and thanks for reminding me.

You bet Roland/BOSS have some fun patents. I am not so sure how they apply worldwide. It was printed in the manual I got with my first OD-1 that both the silent switching and the asymmetric clipping were patent applied for. However the ones with effect and colour combinations are more intriguing ;)

Yes it would be fun to read a compilation of those patents if you happen to have the time some day.

Maybe somewhat interesting side story:
There was this guy that worked at a local music store we’d used to hang, and he was a great guitar player and he was in charge of the electric guitar section of the store and also the guy that went to Frankfurt and that bought all the new pedals for the store. I bought my OD-1 there basically because they were the only ones to carry the latest
and we’d hang around to hear about the latest in the hopes that something really good would turn up, but I also bought it because one of my guitar heroes had been using one for sometime before and that guy always had great sound.

Anyway skip a year or so ahead and the guy at the store told he had been to Frankfurt again and now the guy who had designed the OD-1 had ventured on to his own company and the whole line was at the store. Those were Vesta Fire, but they looked odd and didn’t catch on.
The OD in the Vesta Fire line was very close to BOSS OD-1 only it had stabistors in the feedback loop and used an odd Japanese dual OP. I guess Vesta Fire withered, but when they were launched a heavy sales arguement was that those were designed by the same guy that did the early BOSS designs.

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BJ
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Post by tube-exorcist »

BJF wrote: .....
Maybe somewhat interesting side story:
There was this guy that worked at a local music store we’d used to hang, and he was a great guitar player and he was in charge of the electric guitar section of the store and also the guy that went to Frankfurt and that bought all the new pedals for the store. I bought my OD-1 there basically because they were the only ones to carry the latest and we’d hang around to hear about the latest in the hopes that something really good would turn up, but I also bought it because one of my guitar heroes had been using one for sometime before and that guy always had great sound.

Anyway skip a year or so ahead and the guy at the store told he had been to Frankfurt again and now the guy who had designed the OD-1 had ventured on to his own company and the whole line was at the store. Those were Vesta Fire, but they looked odd and didn’t catch on.

The OD in the Vesta Fire line was very close to BOSS OD-1 only it had stabistors in the feedback loop and used an odd Japanese dual OP. I guess Vesta Fire withered, but when they were launched a heavy sales arguement was that those were designed by the same guy that did the early BOSS designs.
.....
What a tasty story..... unfortunately its only made up utter nonsense.

The Boss OD-1 (v1) appeared on the market in late 1977. Shiino didn't sell any pedals under the Vesta-Fire brand before 1982. So it couldn't have been "one year or so".

The Vesta-Fire Overdrive has absolutely nothing in common with the Boss OD-1 simply because it is a clone of the Locobox Tubemaniax with an added Big-Muff-style tone-control - as already used by Locobox in the Mysto-Dysto. Even the unique Locobox FET-switching - totally different to the Boss FET-switching - can be found in the Vesta-Fire Overdrive.

Shiino existed long before 1982, so if there ever has been a "rogue technician" he must have been from Locobox - and not from Boss - and in no case he founded Shiino/Vesta Fire.
BJF wrote: The OD in the Vesta Fire line was very close to BOSS OD-1 .....
Looking at the circuits every skilled technician should be able to determine that the Vesta Fire Overdrive and the Boss OD-1 have nothing in common.

The Boss OD-1 has the Gain potentiometer in the feedback loop, while the Vesta-Fire Overdrive has the Gain potentiometer to ground.
....was very close to BOSS OD-1 only it had stabistors in the feedback loop....
How important this is sounding: "stabistors"

These mystery "stabistors" - like the widely used MV-13 - are nothing else than 2 diodes in series in a single case:
MV-13.gif
MV-13.gif (7.02 KiB) Viewed 2303 times
BJF wrote: .... only it had stabistors in the feedback loop....
The Vesta-Fire Overdrive not only has double-diodes (stabistors) in the feedback loop it also has normal diodes with a series resistor in parallel to the double-diodes (stabistors) exactly as the Locobox Tubemaniax has:

Image
http://www.locobox.com/tubemaniax.html

The black & white parts in the upper right corner are the double diodes (stabistors) and beside them are the normal diodes with the resistor in series.
BJF wrote: ....and used an odd Japanese dual OP.....
[/quote]
The "odd japanese dual OP" is nothing else than the NJM4562 which is an improved version of the 4558:
http://www.njr.com/semicon/PDF/NJM4562_E.pdf

The NJM4562 was widely used e.g. by FOSTEX in their equipment - so for every skilled technician it is/was far away from being "odd".

So the Boss OD-1 and the Vesta-Fire Overdrive have NOTHING in common and there is absolutely NO evidence that the "same guy who designed the Boss OD-1" (or any other Boss pedal) designed the Vesta-Fire Overdrive too.
"I've noticed there's an inverse relationship between cost of gear and talent. If you need the most expensive gear to get decent tones, then you suck as a player."

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Post by BJF »

Hi there,

Yes as I said an interesting side story and it could really spur a few thoughts

As I said it was a heavy sales argument that these were made by the former designer of BOSS…

At the time you could get a way with somethings at Frankfurt which you couldn’t pull off today…

It is also so that if you placed an order of at least 1000 units you could have your name printed on final product and that from several manufacturers…..

You can still do that though the location of factories is different today.

I also dug out the pcb for a cupboard and let’s see, and yes my memory of such things old may be not so perfect and also at the time I didn’t pay much attention to what month and year things came out ...

Well, firstly yes I am aware of when the OD-1 appeared on the market and as I said skip ahead- and to me it was a long time ago and yes it was probably a few years and not until into the 80’s that the Vesta Fire line appeared.
The model I am talking about did not have a big muff style tone control but an inverting OP amp with some filters making a little slower slope than 6dB/octave and yes a gain control that dubbled as high pass filter at highest setting at a rolloff of about 600Hz so at max gain net filtering would be about the same as an OD-1 except a little brighter and extending a bit lower and so the filter at input was set about 70Hz- arguably two octaves lower than OD-1 but then just about the low E and in that a couple of octaves higher than TS-808
while at lower gains more lows would be present making the total effect a little more see through- however at the time it was very evident where this was going - only I much prefered my BOSS OD-1, while it was evident what had been done to ’improve’.
True you need only change a little to say you are totally different. As seen at the time there was no significant change to the switching of the pedal I am talking about-that you can make the flip flop in various ways is another story while the same function is realized and yes the Vesta Fire I talk about had this keyboard style switch as used by BOSS
Sure there were stabistors and that’s a component that has two series diodes and is specifically made to have a certain forward voltage as per example 1,2V or 1,3V depending on what you need and this used to be a popular component in small power amps, and there was also a second feedback loop so from output of main Voltage gain Op to Inverting input there were two antiparallel stabistors in parallel with a 100K resistor and in parallel with this also a pair of small signal diodes in antiparallel and in series with 10K resistor... oh and the dual Op was 6552
at the time there were no supplier near me circa 1981 or there about that had this chip, but it was typically a part you could find in Japan while not in EC, but suffice to say it’s a dual OP of a slight upgrade kind...
The pedal looked like this
http://www.effectsdatabase.com/model/ve ... rive#forum

Oh yes I have seen several of the Loco Box pedals and those survived a whole lot better on the market than the wedge shaped pedal I talk about above and I recall the Choker being more or less an exact copy of MXR Dynacomp.


All in good fun
BJ
BJF Electronics
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