What's the distortion adding feature of the new $$L console?

[Ralf Biermann]

There is a little miracle behind it: if the peaks of the sine wave are a little bit more flat, this can be done with only the uneven harmonics, which sound bad, but as well as with the 2nd and 3rd harmonics, which sound fine.

So even if the output looks the same, the difference is in the content of the harmonics.

Again: I think a tube amp is best for this product of harmonics. But it should not be a single ended stage, because it would be a sound effect, but a differential stage, which has just a very minor product of harmonics.

Best Regards
Ralf

 

[Guest]

Hmmm... What about something like 12AX7 with 12V on anode? Should work. No need for a bias shift, just a double pot to balance between a tube and an inverting OpAmp.

 

[Guest]

[quote author="mediatechnology"]Hey Wavebourn I still like your diode idea.
[/quote]

Thanks! But 12AX7 will work as well. Or 6N23P may work better on low voltages.

Where's Kev with the screwdriver?

Hmmm... In PD?
:shock:

 

[CJ]

Everybody has their price.
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So, Keef, ol buddy, ol bloak, howa doing? :grin:

I pledge $10 to the "let's get Keef fired" campaign. :guinness:

 

[Svart]

svart: Hey Chris once we learn what SSL is doing does the person making the correct guess (if there is one) get a prize?

:green:

I suppose so, what would you like?

Damn I was so busy today debugging an opamp problem at work, but I was actually going to get online and bring this topic back up..

 

[Svart]

well you've done so much work on this and got to a pretty cool outcome, even if it isn't like the ssl idea, you came up with something i would like to build.

:guinness:

 

[Kev]

[quote author="mediatechnology"]Kev was apparently in the same room as one of the SSL preamps with VHD with a screwdriver in hand. (Do I have it wrong Kev?) Apparently he wasn't able to actually get a cover off.[/quote]
yeah ... nah
I missed the chance ... if there ever was a chance to lift the lid
I may get another chance once that demo unit has done the rounds once

at the moment I'm keen to swoop on a Junger Level Magic
and near by
there is an original uncovered DBX VCA and DBX alignment jig ... with some documents

 

[Svart]

bumpity bump.

I'd love to build this..

Wayne what was the last proto you did on this?

 

[tony dB]

a little fuel for your mindspin guys:

SSL has tremendoesly reduced the powercomsumption of their beast, as the ecologic element isn't to be ignored these days.

From what I've seen, the difference in powerconsumption is huge compared to 4K/9K series.

What devices deliver ae 2nd/3rd harmonics at low powerconsumption?
Or is this only an SMD advantage?

 

[Guest]

[quote author="mediatechnology"]svart;

It was pretty much like Wavebourne's post with the diodes. I had a few pots in there to offset things so I could dial it in using RMAA to set the second/third ratio.

http://www.groupdiy.com/index.php?topic=18681&postdays=0&postorder=asc&start=96[/quote]

I dunno, may be Roland patented it? I saw something similar in their guitar pedal; I swear I did not steal from them, but as soon as it was put in production it might be patented. :roll:

 

[Guest]

[quote author="mediatechnology"]The Eric Johnson demo cut I posted was done with this one but without much gain in the middle. What is shown is way too much maybe I used some attenuation in the middle as well. Throw in some offset pots too:

http://www.groupdiy.com/index.php?topic=18681&postdays=0&postorder=asc&start=74[/quote]

Some DC bias needed in order to get even order products.

 

[TomWaterman]

I tried to ask when I was there but they didn't say specifics...

going back again at some point so I'll keep my ears peeled.
Obviously I'm not going to disclose any secrets and I doubt they would to me either!

The Duality VHD knob is quite fun really, and it needs to work at high gains...ie you run the line input into a second mic pre which has gobs of gain and you have to drive that before you can hear VHD working heavily. Its quite subtle until you crank the gain then it can get brutal.

There is a definite difference between 2nd and 3rd settings on the knob...2nd sounds like a db of compression along with a transient slowing...

3rd really brings out slap on snares and percussive elements etc.

-Tom

 

[Rogy]

Don't know if this is helpful in the context of this thread, but it certainly is very interesting:

http://www.pmillett.com/etf_sod.htm

check out the PDF!


Regards,


Rogy

 

[AnalogPackrat]

Hey, thanks Rogy! Very interesting presentation and circuit...

A P

 

[clintrubber]

FWIW, that pdf has been around for some time. Nice stuff! Would be nice if we could put an ear to those sound-examples. Did I miss anything ?

 

[barclaycon]

This isn't the first time that SSL have had a crack at adding harmonics.
Remember their EQP option? In response to Power Station's request for a more 'Pultec' sounding EQ they did this version. It was identified on the desk channels as being the ones with orange caps on the Bass EQ knobs.
I remember seeing a box built by Summit many years ago that was a line amp with a 'warm' control on it. Summit made great sounding valve EQ's and limiters. They identified what was 'warm' about valve electronics and you could hear it. I think they were designed by the guy who does Crane Song.
One final thing about distortion. When I was a tape op about 28 years ago, the band I was working with wanted a really distorted guitar sound for the solo. So we paralleled the feed to the tape machine and made each track have a higher and higher record gain. When the guy did the solo, the VU's just pinned the endstops. The loudest track sounded completely over the top and we laughed about it and kept playing it back. That was the take we kept and went onto the album.
I think I might have a go at that harmonic multiplier circuit.

 

[Guest]

[quote author="barclaycon"]
When I was a tape op about 28 years ago, the band I was working with wanted a really distorted guitar sound for the solo. [/quote]
Occasionally you can big yourself up and name the band - I have a feeling you and Keef (SSL Tech) may have been involved in two different songs in the top 10 at the same time

 

[barclaycon]

The Cure - 10.15 On A Saturday Night
from 'Three Imaginary Boys'.

 

[SSLtech]

[quote author="barclaycon"]This isn't the first time that SSL have had a crack at adding harmonics.
Remember their EQP option? In response to Power Station's request for a more 'Pultec' sounding EQ they did this version. It was identified on the desk channels as being the ones with orange caps on the Bass EQ knobs.[/quote]
That much is true... however, there was no harmonics or distortion generated, beyond what was done in all the other EQ's (82E02 was the only other option I recall at the time that the EQ-P was introduced... the 82E242 ["black-knob"] and '292 [original G-series] alternatives came later.)

If you look at the schematics, it's just a differently-shaped sidechain filter, which was also designed to interact in the same way that Pultecs did.

Being passive, the Pultec basically drops the signal level by around 20dB. The make up amplifier then has a corresponding 20dB of gain. You get a "boost" (of let's say 18dB) by reducing the attenuation at that frequency point. However, if you "overlap" two bands, you can't "gang them up" for 36dB (2x18dB) of boost... because the available boost "runs out" as it were...

So the interaction and the bandwidth/boost interaction (widening the bandwidth on a Pultec noticeably reduces the available peak boost) was designed to mimic the Pultec's behaviour, because -as you rightly pointed out- people went to the Power Station becasue of their mighty, mighty rack of Pultecs. SSL wanted to sell Power Station a console because they were trying to crack the American Market at the time. (Andy Wilde -later of Euphonix- was sent over by SSL to coordinate a sales 'push' in America in about 1984... right about that time... the rest is history!)

So the official SSL wording was along the lines that that the EQ-P was 'designed to emulate the curves and behavioural character' of the Pultec equaliser... The power of suggestion did the rest. There was no attempt at distortion or waveform reshaping other than by frequency-related amplitude gain. -Basically if you put a sinewave in, you got a sinewave out, with gain being the only variable.

I don't think for a minute that SSL intended to decieve people into thinking that it added distortion; that simply wasn't their way of doing things- but when people started to 'buzz' about the "pultec EQ option, the majority of the interest was in the unfounded supposition that it "warmed" the sound.

-I think I still have the schematics at home... It was never liked as an EQ. We tried it, we didn't like it. I don't think that anyone ever liked them in fact... -That is to say that I certainly never met anyone who said that they did!

Forgive the interjection: info included just for clarification... -See the rumour began all those years ago that SSL was 'harmonically imitating' the Pultec, and people spread around the misunderstanding that the EQ-P included 'tube distortion' simulation. Ever since then I've felt bound to correct the misapprehension. -Were it in fact true, I'd have cloned it as a separate effect by now... and I'm sure that people would have lobbied SSL to make it accessible without the EQ itself, so that they cold use it as a separate processing option... -I know I would, for sure!

Keith

 

[barclaycon]

Hi Keith.
As you say, there were many different versions of the SSL eq and it was particularly annoying to go to different studios that had strange variations.
The one that caused much consternation was when they replaced the peak/shelf button with the 3 x times freqncy thing.
My favourite version was the 'black LF knob' version which seemed to be a quite good sounding, eminently usable eq. The very earliest 'sharp- slope' eq cost SSL a lot in reputation when they first brought out the 4000E board.
One final thing, did you ever try the Masalec EQ board? Leif Mases made these retrofit boards and I must admit they sounded great; particularly the top end. I tried to get a circuit out of him (without luck) and ended up drawing one out myself.
Martyn