[NEW VERO] John Hollis "Flatline Compressor" on Vero + Circuit Analysis

[ulysses]

hey guys

i just built the john hollis flatline compressor from a new vero i just made. its a nice circuit.

21x10 vero to fit in a hammond 1590b.

comes with a bit of a writeup on how it works and my experiments with it.

check my layouts in the gallery. http://aronnelson.com/gallery/ulysses

cheers
ulysses

note: i had to upload them as png format becasue the galley was not accepting the gifs i was trying to upload.. something about being unable to make thumbnails..

[MartyMart]

You got it all worked out then .... what LDR or Vactrol did you go for ?
Pretty impressive little comp isn't it ??

[ulysses]

i used a yellow 5mm led and a 50k LDR with 40ms rise/10ms decay (that was the best i could buy locally).

sounds really nice

its a nice and easy comp for people to build.

cheers
ulysses

edit: theres a pic of the LDR/LED i built on the layout

[markm]

Congrats Ulysses!
It is a nice Compressor. 

[newbie builder]

Awesome layout and information Ulysses, thanks! I'll have to add this to my build list.

[vortex]

I like this circuit too. I used a Silonex NSL32 , which seemed to work well. 

I wish there was a way to control the attack time...

[ulysses]

I wish there was a way to control the attack time...

you could buy an ldr with slower rise

mine is 10ms, which is fairly fast. i have seen them with 40ms rise, 80ms rise, 120ms rise, etc..

cheers
ulysses

[ulysses]

hey guys,

just to let you know i have just re-uploaded this one after there were gallery problems..

cheers
ulysses

[markm]

What's your final opinion of the Flatline Ulysses?

[ulysses]

hey mark

yeah its a nice compressor. i think i would like to try it with an even faster ldr - maybe 10ms rise 10ms decay (i dont know if they exist). i found hammering on from silence gave 40ms (rise delay of my LDR) of boosted hammer-on, which you dont want - sort of sounds like a mini-pop if you listen closely.

you quickly notice how much practice your playing needs with the sustain right up!!

i also found that it boosted the hum of my single coils quite a lot when playing softly - but that is prob a complaint of most compressors.

i found that the large output cap popped quite a bit when you had the compression all the way up and you switched into bypass. changing the 3pdt wiring to grounded output fixed this up quite nicely.

overall it achieves the goal with a novel approach, gave smooth sustain with good response (40ms rise, 10ms decay).

the build is an easy one which i would recommend to anyone who is interested in building a compressor.

cheers
ulysses

[blanik]

if i uderstand what you guys are talking about it means the release time (and attack) is controlled by the type of VTL we're using... i think MarkM used the VTL5C2 with great sucess (maybe it was MartyMart?) but judging by this datasheet i found the VTL5C1 would be even better... (faster times) if i got all this right the C1 would sound more natural?

am i right??

R

[ulysses]

if i uderstand what you guys are talking about it means the release time (and attack) is controlled by the type of VTL we're using... i think MarkM used the VTL5C2 with great sucess (maybe it was MartyMart?) but judging by this datasheet i found the VTL5C1 would be even better... (faster times) if i got all this right the C1 would sound more natural?

am i right??

depends how you define nautral i guess compression isnt really natural at all becasue it takes away the dynamics of your playing.

the C2 has a fast take up time and a really slow release time. the c1 & c3 are faster on both rise and decay.

mark is using the c2 which is like having the release time set low and the attack speed fast. so its personal preference i guess.

personally i like fast attack and fast release. i will mark down a vactrol to buy from smallbear on my next purchase from there.

cheers
ulysses

[markm]

I think alot depends also on how a compressor is used.
Many guitar players that are "confused" by comps tend to mis-use or misunderstand them. I've seen more than a few try to use a Stompbox Compressor the same way one would use a distortion or overdrive......you know the routine, plug it it in, dime all the knobs including the guitar controls, play away and then state that "it sucks".
Well, used as such it would I suppose.
But, when used properly a good guitar compressor is almost like another instrument and it's short comings can sometimes be used as an advantage in playing.
I would think a faster overall attack and release on the Vactrol would certainly make the circuit more "transparent" however, would such faster times lead to a less active control of the compression using the comp pot? In other words, the Compression potentiometer would have a less noticeable effect with a faster Vactrol vs. a slower one?

[ulysses]

I think alot depends also on how a compressor is used.
Many guitar players that are "confused" by comps tend to mis-use or misunderstand them. I've seen more than a few try to use a Stompbox Compressor the same way one would use a distortion or overdrive......you know the routine, plug it it in, dime all the knobs including the guitar controls, play away and then state that "it sucks".

yeah i agree with this. i sat down with a boss compressor about 10 years ago in my teens - i didnt know what to expect and couldnt get it to give me endless sustain like i presumed it would. i moved onto effects like heavy modulation and distortion.

i think like most effects its important to understand how they work to get the most out of them musically.

I would think a faster overall attack and release on the Vactrol would certainly make the circuit more "transparent" however, would such faster times lead to a less active control of the compression using the comp pot? In other words, the Compression potentiometer would have a less noticeable effect with a faster Vactrol vs. a slower one?

the "sustain" knob on the flatline is the "multiplier" of the "boost" stage. the flatline works on the principle "boost low input signals". with the "sustain" knob all the way up the entire input signal is boosted to 100% output volume "flatline".

with the "sustain" knob at 75% the multiplier is to bring input signals up to at least 75% output volume. so heavy signals will still go through at 100% output volume and all signals lower than 75% output volume will be brought up to 75% output volume.

so the "sustain" pot would not be less noticable, it would still raise the low input signal to whatever "boost" you set with "sustain" pot.

with slow decay, instead of keeping the output volume at a constant 75% - you would see 500ms of incorrect volume adjustment ie, hammer on your guitar and the boost drops right back - it will now take at least 500ms to boost any subsequent quiet signals back up to 75%.

so thoeretically, slow decay on the LDR would be like turning an imaginary "attack" pot right down.

so marks vactrol would have the following effect - drop back very quickly when hammering on from quiet, and rise boost slowly when going from hammer on to quiet playing.

some people will prob really like this. it would give a more more dynamic feel to the compressor instead of being hard lined.

i hope i have explained it a little bit better than before. its quite difficult to explain. sort of like one of those 3d eye images.. just look through the damn thing!!

im keen to give both vactrols a go to see how they compare.

cheers
ulysses

[markm]

I see what your saying here.
Makes sense to me!
The slower Vactrol is actually going to make the circuit sound more "squishy" .
(Hoe's that for a technical term huh?!) 

[blanik]

maybe a comp with switchable Vactrols? a C1 and C2... to suit your style...

i think the comp level sets the treshold at wich the opamp starts to raise the fading volume (correct me if i'm wrong)...

when your not playing the led is off, thus boosting the opamp at max but when you hit a quick note you want the note to sound as if no comp was there, you don't want to hear it "fade in"... so a quick led time is better...

i think i'm more looking for a sustainer than an actual comp (the flatline seems perfect for that)


R.
edit: Ulysses posted his awnser during my typing...lol