Sunday, 6 July 2014

Diamante Compressor

I'll add a Diamond Compressor layout at some point, but this one was a must for me and I'm surprised it's taken me this long to do the layout.  This is Fred Brigg's stripped down version of the Diamond, which is essentially the same but without the Tilt EQ section of the circuit or the (admittedly funky) colour changing LED depth indication part.  As someone who tends to leave EQ around the middle default setting anyway this made perfect sense for me, and as the omitted sections added a lot to the circuit size, and now with only two pots, it means it will be an easy one for a 1590B.  My rack tray thanks you Fred :o)

The other thing Fred changed was the input buffer which is now opamp instead of BJT, but the main compression part and envelope detector is as per the original and so should be comparable.

The circuit uses a VTL5C3 Vactrol which is 10M off resistance.  I'm not sure whether you will get a low enough on resistance with a 10M LDR and LED combo, but by all means give it a shot and let us know how you get on.  If you do want to try an LED/LDR instead, just use the points shown where the Vactrol is connecting.  Right hand side is LED with cathode at the lower connection, left side LDR.

Read more about it on Fred's page here.  I can't find a video of the Diamante, so here's the Diamond to give you an idea what to expect







[15th July 2014 addition]

And this is a modified version to include the tilt eq.  I have kept it true to Fred's Diamante philosophy and swapped the BJT buffer used in the original for an opamp buffer, using the second channel of the opamp added for the eq.  Because the tilt eq is inverting I made the buffer inverting too so that the output will be back in phase.  This won't matter to most people but thought that if maybe a bass player wanted to use this with a blend circuit, then having the output out of phase could cause cancellation issues.  I noticed before that the original tilt scheme from the 70s preamp also has an inverting buffer, so this is also in keeping with that.

So this one is basically an all opamp Diamond Compressor, just omitting the funky LED

[updated 11th Nov 2014]

51 comments:

  1. YES! I have been waiting for this one for the longest time. I have everything on hand except the VTL5C3 (but I think Tayda LDRs should work), and will try to get this one checked out ASAP.

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    1. If you do have any LDRs then socket the position and give them a whirl. It would be great if we could get a similar sort of response out of the pedal with a 3p LDR that we could with an expensive vactrol.

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    2. I just ordered some 5C10 and 5C6 vactrols from a lameo site with $10 shipping. Didn't order any 5C3s though. Any chance either of the ones I have on hand will work alright?

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    3. 5C10s are only 400K at full dark, 5C6s are 50M. Looks like I'm ordering some 5C3s from small bear.

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    4. So I did some research, and the GL5539 LDRs are very similar spec-wise to the VTL5C3 (10M off, 30-50K on). I have ordered them (20 for $5), and will get them by the end of the week. We shall see.

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    5. Tag it, and we have another winner here. This is just a really great sounding optical compressor, super transparent, works equally well with guitar and bass. I used a homemade Vactrol consisting of a 3mm yellow LED and a GL5539 LDR, and it works perfectly!

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    6. Awesome Ross thanks for verifying :o)

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  2. I have a PC123 Sharp,will this work for my vactrol?

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    1. No I don't think you can use it, the PC123 is an LED controlled transistor, you need an LED controlled resistor like a vactrol or LDR/LED combo

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  3. Mark.
    Do you think this is better than the pig phil tone?

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    Replies
    1. i didn't like my phil tone....

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    2. I've never used a PT so can't answer from experience, but a lot of people have said the Diamond is the best compressor they've used

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  4. Any chance we could get a daughter board for the tilt EQ? It sounds interesting and I would love to try it out on this and other builds.

    Thanks for all the great layout IvIark

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    1. Check out the revolutiondeux post on the Diamond Comp and he's got the schem for just the tilt EQ by itself there

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    2. In the forum area of this site, John K. posted a vero layout of the tilt. It's awesome!

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    3. Thanks a.! I feel a little Canadian when I say that out loud.

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  5. So i thought i had vtl5c3's lying around but they were actually vtl5c1's. I tried using some LDR LED combos but the circuit keeps blowing up my LED's. any ideas?

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  6. Okay- I got this one working with a home rolled LED/LDR combo and it works, but it has some strange fluttery sounding pumping, throbbing almost tremolo with a low depth effect on the sustain- this increases as I turn up the compression. I got some VTL5c3's and it makes this problem worse, but the circuit now distorts with the VTL5c3's. I've gone over the board a million times now over the course of 2 months and cannot find anything. So how do these voltages look

    IC1
    4.45
    4.45
    4.03
    0
    4.24
    4.45
    4.45
    8.92

    IC2
    4.43
    4.43
    4.43
    0
    4.25
    4.12
    4.45
    8.92

    The collectors on the transistors show 6.93v each
    The vactrol shows 7.62v on pin 1 and 8.91v on pin 2 (LED - and + respectively)

    no voltages on any other pins of the transistors or LDR side of vactrol.

    Anything look weird there?
    Thanks for all the help you give! I know this is the 2nd problem circuit ive posted in a row and i apologize. i'm trying to get this and the delay working cuz they're driving me nuts. out of all my problematic boards these two are soooo close and theyre the circuits i soooo desire. deep blue and diamond comp.....mmmmmm.....

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    1. IC voltages look perfect. Have you tried other LEDs and LDRs?

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    2. ive tried two different VTL5c3's- but they distort. and my homemade optocoupler gets this fluttery thing going

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  7. If anyone has built the Diamante Plus and had problems, move the EQ3 wire one row up. DOH!
    Layout now corrected and verified by Miro

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    1. Doh! This just got me and I came here to post that the plus wasn't working... I can double verify it after making the EQ3 wire adjustment. :)

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  8. Hopefully this is not super obvious but should I use a momentary or latching switch for this build?
    Thanks

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    1. The switch selects whether the hi cut is in circuit or not. If the switch was momentary then the high cut would only be in circuit as long as you were holding the switch which would make it fairly pointless, and so you would always use latching for something like this.

      Momentary switches are used very seldomly in these layouts. For something like tap tempo or switching through modes in some more advanced ICs then they are used a couple of times. But always assume latching unless momentary is specified in the layout.

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  9. I finished this build and love it!! Thanks again. It seems to work fine but I don't notice any difference when I hit the hi cut switch. Is it really subtle and I am just not hearing it? Also, I occasionally get some radio frequency sounds. Anything I can do about that?

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    1. The switch just add a cap to ground at the output creating an extra low pass filter. If you want a more dramatic effect, socket the 2n2 cap and increase the value until you get the response you want.

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  10. HI,
    just finished this comp. Work at the first time !!!
    It is the best comp i've never seen, heard ! :)
    I love it ! very simple to use…

    Franck

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  11. What is the LED+ line coming in on the right side of the board for?

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    Replies
    1. that's for the + side of the led to connect to. the negative end goes to the switch. some layouts have a resistor for the led on the board, but most do not which is why you see the LED wired the way it is seen under the offboard tab.

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  12. Hi iviark

    Already build this..againn..and this is awesome,,3mm yellow led and LDR is good enough , Oh yaa, hi cut switch is really subtle,,but i was try to connected hi cut SW 2 to "volume 2" , and yeahh,,hi cut is work ,,damnn. thanks for your layout

    agung M

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  13. Hey, I happen to have some GL5539 LDRs - So I am going to give this a shot.

    Just FYI: since Jan 2015 you can still find many new layouts in the forums:
    http://guitar-fx-layouts.42897.x6.nabble.com/

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  15. I got this built and the LED is working. My first LDR burnt out (I think, not sure why), but I replaced it but I am still not getting any output. When I do an audio probe I get good sound all the way to the 10n cap (lower left). on its left leg it sounds great, but on the other side it is all lower volume and very distorted. That means everything feeding the 2n5088s is also distorted.

    Now, I am not sure if I could move the LDR back (away from the now 3mm red LED) and make the enclosure darker and that would fix it, but it does not seem likely. That 10n cap just seems wrong. I also have to say I don't have the LM358 so I was using a TL072 instead (I think a TL062 would be better if I had one because it is "low output" where the 072 is "low noise".)

    Anyway - depressing. The Love Squeeze sounds better by comparison. I figured out the Love Squeeze is not so bad, if you turn down the "compression" know you really just turn down the input to the diodes but they still compress, they just don't break up so much.

    Anyway - if you are reading this and wondering where everyone is hanging out, try the forums (as of Jan 2015): http://guitar-fx-layouts.42897.x6.nabble.com/

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  16. I finally figured out my problem. The volume pot lug three has TWO connections - one to switch and one to ground. I missed the connection from the pot to the switch. I guess I just figured I had all three lugs filled so I was done.

    Anyway - this compressor sounds perfect now, even with humbuckers. No hair at all even at full volume; on the effect and on my pickup. That is how I like it. The LDR/LED setup was actually easy.

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  17. I actually got the correct IC (LM358) for this today and my guess was pretty accurate, the TL072 pushes it a little too hard. It sounds cleaner now. I also added n HPF on the output which makes it sound a little brighter which is always nice for a compressor. It helps.

    I just added a DPDT switch (from the volume pot #2) and put one side straight through, and on the other sides bridged the poles with a 10n cap tied and added a 63k resistor from there going to ground.

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  18. Building this and found a handwritten schematic on Briggs site. Decide to play around and make another schematic. I believe this to be correct with the build and any errors are mine and any correction welcome. Associating the schematic with the build helps me to figure the circuit and what it is doing out better.

    https://drive.google.com/folderview?id=0B87ADm67wAAYUWo3RXVYaFB2MzQ&usp=sharing

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    1. I think this schematic has an error. The two 10K voltage dividers in the top LH Corner say they output "ENV" but I think it should read "VB" . Which, BTW is how Fred Briggs has drawn it. A small but vital error I reckon!!

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  19. Would anyone know how to implement that cool LED? thanks :)

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  21. Hey, I built the Diamante Plus version. It seems to work, but there is some nasty clipping at high compression settings. It's becomes more if I add a boost in fron of the comp and it sounds like, it's after the tilt eq, cause it also depends on the eq setting. I'm wondering, where it comes from and how to adress that. Do you have an idea? Might that be the vtl5c3 or the 100uF cap, cause it's only rated at 25V? Thanks!

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    1. I figured out, that the clipping is gone with a cheap power supply which I measured about 12-13Volts. Also the compression seems to work better (more pronounced/strong in a good way). Just the comp poti doesn't seem to work right, cause the compression seems to be fixed. It just changes the input gain. I'm going to change the diodes/transistors - might be some faulty one - don't know. Do you have some Ideas? Thanks.

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  22. Hello.
    i built a couple of this diam comp ( honestly i used the sabrotonelayout, but that doesn't matter ). Both of them are "working" in the same way:
    - eq switch working
    - all pot seems working
    - hi cut isnt working ( but i didn't tried this solution posted before:
    i was try to connected hi cut SW 2 to "volume 2" --> i'll check

    the real problem is: i have the same results with and without the optocoupler :|
    compression led is engaged everytime i touch the guitar ( with a stronger signal as i turn on the comp knob ). so, seems to me that the compressor is working.
    i'm not exeperienced with optical compressor, i'm glad if someone could explain me how this magic could happen.

    ( i'm gonna try to make this layout as soon as i can, just to check the differece )

    thanks in advance

    edwin

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  23. Hi
    I'm Building the Diamante plus for the EQ option, but I,m wondering why there is an EQ switch at all, also, the numbers relating to the DPDT do they run left to right going down, or do they run down 123 left and 456 right side. Hope someone can clarify that please.
    Thanks

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  24. Hi! If i want to build this for bass. Is there any changes you can do to make it fit a bass better?

    Thanks!

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  25. Have a look here:

    http://vulcanofx.blogspot.co.uk/2013/07/diamond-bass-compressor.html

    And here:

    http://revolutiondeux.blogspot.co.uk/2012/06/diamond-compressor.html

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  26. Hey Guys,
    Since my diamond comp still distorts at high comp settings I took the multimeter an found this: at the highest comp setting the voltage difference between the two led pins(vtl5c3) is just 1,53V at a very high input signal (telecaster bridge - heavy hitted low strings)
    That's quite low right? If there would be a higher Voltage, LED would be brighter and than there would be more compression and less distortion. Any Ideas, what could be wrong? I really checkt everything for hours and couldn't find something wrong. Any help would be nice! Thanks!

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    1. Also experienced the same situation as yours, however only with humbuckers. with my strat its works without a slight gain as it should but i noticed that the comp works more like volume or gain knob instead. maybe try other types of led. I used a 3mm diffused yellow led, might try a clear one.

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  27. What capacitors do i change to change the freq of the tilt eq? Want to make it like the bass version with 250hz and 900 hz tilt point.

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    1. anton, look here http://vulcanofx.blogspot.de/p/tilt-eq-calculator.html

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