modification Optimod 8100A

[Robert Bass]

Re: modifacation Optimod 8100A

I remember Bob saying that the analogue meters were very expensive to obtain,hence why they fitted led meters on all but the main "vu meter".
The pcb's would be easy to make,but certain components may be now hard to get.
Also the metalwork for the box itself may be expensive.
Lets be honest,the 8100a is built like a tank!

Why not just use one of those 3 rack space, enclosed computer units as a "box" replacement for bulding the 8100's? Aren 't those things pretty durable?

Just curious...

R

 

[Henrimaximaal]

Re: modifacation Optimod 8100A

Hello sir, can you pls tell me the settings you used on both the MS and MF presets on the 8200?
Kind Regards, Henri

I have uploaded the 8200 midslow track of Tina Arena test track.
Also i am currently uploading 8200 midfast track of the same,and also the Fm Ultramod and cp2013 comproc version.

The reason i uploaded both midslow and midfast versions is that the nearest multiband setting on the 8200,to the xt2 is midfast.

I prefer the midslow,the 2 settings are quite different on the 8200.
The settings of both are modified from the default presets,also i am using aes/ebu in straight off the cd player,so the background noise floor is very low.
This can also alter your perception of (lack of)breathing on the track.
I have done a few internal mods to the 8200,but nothing like the 8100a/xt2!

If you want the 8200's settings for both presets,let me know.

 

[NoTimeForSleep]

Re: modifacation Optimod 8100A

I would also like the preset if you are so generous. Also, what mods have been done to the 8200?

 

[BROADCAST]

Re: modifacation Optimod 8100A

Ok,here are my settings.
Remember on the test tracks i use aes/ebu in from a cd player,so the agc gain reduction will only match if you use the same input.
Also the D-I REF PK LVL = -9.5DB

MIDSLOW MIDFAST
--------- ---------
AGC DRIVE = 10 11
AGC REL = 0.5 2
MULTIBAND DR = 16 13
MULTIBAND CLIP = +0.4 +0.4
LOW BASS BOOST = 3P+2 3P+2
MID BASS BOOST = +1 +1
PRESENCE = +1.5 +1
BRILLIANCE = +4.0 +4.0
FINAL CLIP DR = +1.0 +1.0
GATE THRESH = -44DB -44DB
HF CLIPPING = +0.5 +0.5
DJ BASS BOOST = ON ON
BASS COUPLING % = 0 0
DOWNWARD EXP = OFF OFF
30HZ HPF = ON ON
AGC = ON ON
BASS CLIP THRESH = -6DB -6DB
PHASE ROTATOR = OUT OUT
BAND 1 OUT MIX = 0.0 0.0
BAND 2 OUT MIX = 0.0 0.0
BAND 3 OUT MIX = +0.2 +0.2
BAND 4 OUT MIX = 0.0 0.0
BAND 5 OUT MIX = +0.2 +0.2
BAND 3&4 COUPLING = 0.0 0.0

Also regarding other mods,i had a 6khz whistle received on a tuner when set for stereo.
I tracked this whistle down to some 32khz sample rate being induced in to the 8200 stereo encoder,mainly picked up by the mpx lp filter inductors.
Also while i was sorting this out i also sorted out some mains hum picked up by the psu's ground system.

I have also seen the whistle problem on several other 8200's.
Note that if you use the analogue l/r out,these are fine,only the mpx out.
I have the before and after test results if interested.

 

[kissgl]

Re: modifacation Optimod 8100A

Goran,
I have uploaded the Tina arena track,recorded from my tuner,from the 8100a/xt2.
Where do i start with the modifications?
Replaced all important 072 opamps,Replaced all electrolytic caps for low esr caps,gate modification,fitted band 1 clipper in xt2,changed resistor values so that band 1 clipper clips at -1db from band 1/2 combined clipper,raised band 1 limiter threshold by approx 2db,so now band 1 clipper clips more often,but combined clipper has 1 db headroom for band 2's contribution.
The bass mods do not alter proof conditions.
Put band 6 limiter control back(like xt),but with mods.
Band 6 can only limit as much as band 5(like xt2),but releases independantly.
On dull material,band 6 shows less average limiting than band 5,so lifts the top end somewhat.

The reason for the breathing you mentioned,is because the dual band agc(8100a) has been left at my default setting.
This means that on old recordings,the agc still has -10 db compression,whereas hypercompressed tracks compress the agc to -20db .
The reason i did this was to keep the agc density about the same,as the bass and master band start to progressively release slower.

The xt2 attack and release times are as standard,i may fit a variable clipper threshold circuit on band 6 only,to give 0-2db of lift to add a bit more sparkle.
As the xt2 soulds fairly clean,i think i could get away with a touch less clipping on band 6.

With regards to your XT2 mods... Very interesting reading here! I'm not yet an XT2 owner at this time, but searching patiently to obtain one. Nevertheless, would you be willing to share the component/resistor value changes you've made? I have an 8100 and would like to have a complete pair someday to experiment with.

kissgl sends...

 

[BROADCAST]

Re: modifacation Optimod 8100A

Hi kissgl,
Yes no problem,let me know when you get hold of a xt2 limiter.

 

[gtomas]

Re: modifacation Optimod 8100A

I have used your settings,and have set the xt2's bass eq to 4db boost(i am sure yours is similar).
Also i have a switch inside the xt2 that i can flick between standard xt2 or my combined mode,i left it in xt2 mode to match yours.

Apart from the bass,the rest of the balance should sound the same,except for the opamps etc.

Broadcast,

Never got to thank you for making and uploading those clips... I got very busy at the time and didn't respond. But it was very interesting to hear the same track processed by 8200 and 8100/XT2. There's a noticeable difference in how these two processors handle high-end and in overall texture as well. The mid-slow release setting in 8200 indeed works better than fast overall, but then again there are times I'd wish more fill and also some slight breathing can be heard. The 8100/XT2 strikes the release time compromise exactly right to me.

When you used the 8100/XT2 settings that are close to what I have here, the issues that I had were greatly reduced. I prefer the processor to keep some depth and volume, but then again to be sufficiently "alive" when the music requires it. With 8100/XT2, the gating and careful adjustment of drive can achieve that. Additionally, your 8100/XT2 sounded much more cleaner and fuller. Congrats again on the efforts in mods you did on it!


Regards,
Goran Tomas

 

[BROADCAST]

Re: modifacation Optimod 8100A

Hi Goran,
No problem at all for the uploads,i find it quite interesting comparing other peoples processing.

A good test track is Elton John's song for guy,the piano transients create an interesting action on the dual band agc,a slow release is required here!

I have been thinking of 2 other modifications to try out,modifying the bass eq on the xt2 from a bell shaped eq to a shelving eq.
Also as the audio path is cleaner through the 8100a/xt2(after the opamp mods),lifting band 6 clipping by 1-2db would increase sparkle,and should still sound fairly clean.

I will upload the original track and the 8100a/xt2 processed track to compare.

 

[radiosaur]

Re: I have modded dozens of 8100's and Prisms

Suffice it to say that the 8100A/Audio Prism/MSI CP-803 (rebuilt) is as good or better then ANY current processor-and I'm talking loudness wise too!

Newer is not always better....especially new just for the sake of new.

I would be glad to continue this off list if anyone wants. My email is [email protected]

I'm glad to see you say that. I came to that conclusion after trying dozens of box combinations. I used that scheme on the last two CHR stations I engineered in the late 80's and early 90's, both of them winners, and I still haven't heard anything that sounds overall as good.

 

[BROADCAST]

Re: modifacation Optimod 8100A

I have uploaded the Elton John's Song for guy,the settings were 8100's release at 7,and bass coupling at 3.
The balance here is keeping up some loudness between the piano transients.
The piano transients are more severe in the second half of the track.

Setting the 8100's release to 8-9 would smooth out the release some more,at the expense of loudness.
Turning up the xt2's density would loose too much dynamics.

This is one of a few tracks that causes the 8100's limiter meter to be active,this is quite rare when card 5 is set for "xt2 mode"!

 

[gtomas]

Re: modifacation Optimod 8100A

I've uploaded the Tina Arena track processed with Omnia6 and DSPX. One Omnia6 clip is processed with the preset I'm using on the air (which is a bit closed-in and cleaner) the other is a Hot! factory preset.

Obviously a direct comparison can't (and shouldn't) be made (especially in regards to loudness) as these clips are not recorded in the same environment and settings, but nevertheless with the clips made by Broadcast I find it very interesting to listen to all these different processors on the same track and how they sound! Everything from distortion, vocal distortion, how they handle high-end and high-end transients, how the low end feels and sounds, the overall spectral balance processor maintains, the overall sound texture and character of the processor, how they respond to the energy and changes in music (which I think this track provides plenty of)...

I find this all very, VERY interesting


Regards,
Goran Tomas

 

[BROADCAST]

Re: modifacation Optimod 8100A

Goran,
I have listened to the O6 and DSPX versions of Tina Arena Chains track,my thoughts are as follows.

The DSPX sounds quite sweet,with good detail.
The O6 with the on air preset sounds bloated on the bass,also the midrange definition is not as good.

The O6 hot preset preset has the same bloated bass,and with the extra density,it fills the midrange.

I find the O6 bass on both to be non musical,no character to the bass,just bump bump.
This could very well be my listening system here.

Also i have just listened to the Never ending story track on the dspx,this shows the upper midrange harshness that i have often heard from the BW processors,this i find irritating!

Talking about processors,this is my biggest gripe when comparing the 8100a/xt2 and the 8200,as the 8200's band 3 covers a wide frequency range,i find the lower midrange(and midrange) backs off when a track gets complicated in that region.
The xt2 has 2 bands(band 3/4),for the one band 3 on the 8200.
What i like is the ability of the xt2 to keep the midrange more forward than the 8200,without getting irritating.

I have also compared the Tina Arena chains track to the 8100a/xt2 version ,and i think the 8100a/xt2 holds up very well indeed,raising band 6 clipper on the xt2 a touch would add a little bit more sparkle.

Goran,were all the tracks recorded from a tuner?

 

[gtomas]

Re: modifacation Optimod 8100A

No, they were recorded directly from the processor's outputs...

I agree that 8100/XT2 holds up very well! Especially if you pay attention to the distortion, the 8100/XT2 has the fewest distorted moments here. And it just sounds good... I'd agree that one key thing in 8100/XT2 apparent loudness is the fact that it keeps midrange filled. Of course, these processors would have to be compared directly on-air to judge the loudness differences between them, but looking at the waveform can tell you that 8100/XT2 clips tightly and would be reasonably loud. Perhaps not as loud as the latest digital toys, but not bad either. When we tested the Omnia-6 and Orban 8400 vs the 8100/XT2 on Radio 101 some 4-5 years ago, although I thought 8400 was louder and sounded better, the CE concluded the difference was not significant and stayed with 8100/XT2 (still using it).

The Omnia has a unique sound texture, the specific low end as well as the high end, which many simply adore. On a good sound system the Omnia bass will sound very nice, but it will depend on what you're listening on, at least that has been my experience.

The DSPX sounds alive and I like it's density. Also bass is close to Orban's, which is my personal preference as far as bass is concerned. Keep in mind DSPX's $3750 price tag!


Regards,
Goran Tomas

 

[folkeu]

I have unpotted all the black modules from the 8100a,and the xt2.
Also i have done some careful upgrade/modifications over the years with great sucess.
Also i have unpotted the "Mr gibbs" module from the Unity 2000 processor.
Carefully unpotting these modules took a very long time!

Hi Broadcast,

I have my 8100 down and I think the problem is with a black block.
The distributor in France has no replacement.
I contacted Orban and they do have more evenly.
Can you help me?
I can not send you PM because I have not posted more than 5 times on this forum.
I am in France.
Thank you
François

 

[Unregistered]

Potted modules

Hi Broadcast,

I have my 8100 down and I think the problem is with a black block.
The distributor in France has no replacement.
I contacted Orban and they do have more evenly.
Can you help me?
I can not send you PM because I have not posted more than 5 times on this forum.
I am in France.
Thank you
François

I have some new potted timing modules for XT2, please check the part numbers...

 

[folkeu]

Hi,
It's not for an XT2 but a 8100 !

 

[Kelly A]

This just in... The loudness wars of the 70's and 80's officially ended at the beginning of the 21st Century. Listeners ears expect a permanent truce to the madness that radio inflicted for such a long time.

 

[Kmagrill]

This just in... The loudness wars of the 70's and 80's officially ended at the beginning of the 21st Century. Listeners ears expect a permanent truce to the madness that radio inflicted for such a long time.

Maybe where you live. Certainly not here (in Florida, USA). Stations are every bit as loud today as they were 30 years ago. Some more so, but they do tend to sound a little better doing it. But rest assured, the audio density is as high as ever.

 

[Kelly A]

Maybe where you live. Certainly not here (in Florida, USA). Stations are every bit as loud today as they were 30 years ago. Some more so, but they do tend to sound a little better doing it. But rest assured, the audio density is as high as ever.

I suppose that depends where in Florida. I was visiting in Orlando and Tampa recently, and didn't hear nearly the type of loudness wars that used to occur during the days when stations commonly stacked compression and clipping boxes to lose dynamic range, as is apparently fondly thought of in this thread. In my view, stations who process for loudness do so at their own peril. More than ever, competition for listeners comes from portable devices and streaming. When your average listener, not radio programmers or engineers, tunes into a station and hears music they have on their IPod being butchered by over-processing on a radio station, even if it makes the music appear markedly different, do you think regularly listening to that station for music will be their preference?

Most modern SDR car radios have AGC's built in anyway. Heavy processing forces the AGC into what amounts to wideband limiting, which not only doesn't allow any discernible volume difference between stations, but makes the lack of dynamic range that much more obvious at the receive end.

 

[Unregistered]

I was visiting in Orlando and Tampa recently, and didn't hear nearly the type of loudness wars that used to occur during the days when stations commonly stacked compression and clipping boxes to lose dynamic range, as is apparently fondly thought of in this thread.

That's because today's digital processors make it loud but clean.

Most modern SDR car radios have AGC's built in anyway.

I must have an antiquated radio in my 2014 Toyota Tacoma 'cause it sure doesn't have any AGC action, unless you're talking about the speed-controlled volume feature.