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why dont I just drop a 220pF in there or something then?

My DMM wont read capacitance. Worth a shot or am I dreaming?

Doing voltage now...

Yeah may as well, it still might be too high a value though (Ceramics at 20+/-% Tollerance means that could be up to 266pF).

just to add mine is doing all the same as Tenwatts, almost to a tee, apart from my volume control seems to work fine.

Even does the whine at high delay settings.

im a bit cautious to start unsoldering parts on the board mostly cos Im a bit rubbish at it.

You're probably just pushing too much delay out the pedal (perhaps your 2 x 120pF caps = more than 240pF?) and introducing clock whine at the high delay settings.

I read about the measurements of many original Deluxe Memory Mans delay time, 400mS was an average, 550mS might be a little bit of an overstatement.

No need to start unsoldering yet! Post the voltages up and lets have a look.

Sounds reasonable, hopefully.
So, to be clear, if that 240 is LOWER than 240 it could potentially be a good thing, but would give lower delay times (i dont care so long as they sound nice, 300ms is plenty for me). BUT if its over 240pF itll potentially give rise to shit sound.

That's about the long and the short of it.

The 5k6 resistor, Delay pot & 240pF all contribute to the delay time, push the clock too much (i.e. more delay) it'll become audible.

The lower the delay time the better the bandwidth too so your 300mS would be cleaner than your 500mS.

just to add mine is doing all the same as Tenwatts, almost to a tee, apart from my volume control seems to work fine.

Even does the whine at high delay settings.

im a bit cautious to start unsoldering parts on the board mostly cos Im a bit rubbish at it.

You're probably just pushing too much delay out the pedal (perhaps your 2 x 120pF caps = more than 240pF?) and introducing clock whine at the high delay settings.

I read about the measurements of many original Deluxe Memory Mans delay time, 400mS was an average, 550mS might be a little bit of an overstatement.

No need to start unsoldering yet! Post the voltages up and lets have a look.

disappointingly mine is behaving the same way.
v3205, jumpers are correct. Both delay chips sound distorted as hell.
At some points in the bias travel, I get no signal too.

Hopefully there is a fix for this.

Well no signal with the blend on fully wet would be normal when twisting the bias control, BBDs only work within bias.

@tenwatt
IC4
1.8mV
4.72V
6.58V
6.58V
7.94V
5.96V
4.72V
8.2V

Pins 2 & 6 should be the same voltage for a 50% duty cycle square wave, these are rather different... something wrong between your clock & bbds.

Your ground (Pin 1) shouldn't have voltage on it... being ground and all.

Pin 5 is a littleee off (D2 should drop about 0.6v to make Vdd 14/15th of Vgg) but it shouldn't hurt I don't think...

Keep looking, hopefully pushing down IC2 & 9 has solved your issues.

Interesting.  I was thinking the 3005's were mostly in vcr's.  I never thought of karaoke machines.  I'll have to check some garage sales next summer.
 

I didn't know that they were using the 3008's for the TTDMM.

Josh

I'm assuming the TTDMM uses 3008s, the XO DMM does and it would make sense now it's cut down to 550ms, 4 x 3008 = 2 x 3005, 3008s are a lot more abundant and in fact, most of the fakes are just 3008s.

VCRs did occasionaly use BBDs but it was only for a short delay I beleive (something to do with matching audio/video, don't know the specifics) so a 3005 is probably excessive, I remember someone posted they found an MN3010 in one (reallyyyy rare, used in the first Re-issue A/DA Flangers). BBDs can also occasionally pop up in old stereos/music equipment for either 'Reverb' or Echo but I wouldn't wanna invest the time and money in pot luck finding them digging through junk.

But yeah, old 80s Japanese Karaoke machines is where i'd look if I was gunna. They're mentioned on the Datasheet.

aside the point perhaps but the DMMwTT current manual states max delay 1100ms, so thats 4 x MN3005, or 8 x MN3008 (!)

Didn't you know the story of the current DMMwTT? It does use 4 x 3005s for 1.1s but MN3005s being as rare as they are, EHX ended up with a bunch of fakes and had to sorta back track on the design, they claim to have gotten out almost 1000 units though.

Little test for ya, try swapping the BBD positions and see if the first remains clean.

I just say this cause I once had a 3208 that distorted like hell, something to rule out.

Then post voltages and check all your values in that area.

Try with a strat or something too just to rule out your pickups overdriving things (I doubt it but it's always good to rule stuff out).

Gain 1 & Bias 2 will be highly interactive, this is a flaw in the design so keep playing with that.

Did you remember to make R11 & 12 47k in the Compander?

Once that's sorted adjust Gain 2 to stop run away repeats.

If both pins 2 & 6 of the 3007 have the same voltage on them (most likely around 3-5V) that should show the clock is working.

Just had a nice little idea here if you are loosing an Op-Amp, add a charge pump/15v reg and we could use theseee... http://www.smallbearelec.com/Detail.bok?no=247

Or ya know... when it comes about people could just use those and a Road Rage, just thought it'd be a nice use for them as the Aqua Boy only had 300ms originally any way and it's always nice to support a supplier.

3005 or 3205 version?

Done the correct mods to work with the version you're building?

All ICs properly socketed?

What are your voltages on all the ICs? Especially the BBDs & 4047.

Have you actually tried to bias the BBDs, if they're not biased you wont get an output.

Edit:Bean Beat me there.

Not to mention the increase in postage due to christmas orders probably slowing stuff up.

thanks djaaz...

i have another question....can i substitute the ne570 with the sa571 or v571??? thanks everybody!

Yup.

Check DIY Stompboxes for Merlins 'Equinox' Reverb, uses 2 x PT2399, pretty sweet for the circuit simplicity.

I think I can actually make it tighter and smaller with more component space, 4 layer boards FTW!

4 layers!  Epicness
Hmmm I am very interested in this now... having played with a boss version once, it is an awesome unit to totally change your sound for a song without changing guitars

Yeah, 4 layers just make Power or V.Ref & Gnds sooo much easier and allows for a tighter and neater lay out... it does mean the boards are pretty expensive though unless you buy 100 (as this was done with Express PCB which is pricey unless you bulk buy) much like the Bad Stone run I helped organise previously... which I think were around $10 a board, can't think off the top of my head.

This is great for a 1590B but i'd love to see a deluxe model (that's basically my entire pedal board, 1590B versions of things for gigging easyness, then deluxe versions to experiment at home and in the studio) so I wonder if there's a project Bean could produce... after the next 30 or so on the way haha.

Definitley handy, even if you're not going for Acoustic it can add a great 'sparkle' to your sound and stacks well with other effects, it's like a dual use EQ.

Thats awesome!
What a cool pcb layout,must have a bit been tricky sizing it for 1590B
Great build!

I think I can actually make it tighter and smaller with more component space, 4 layer boards FTW!

Cheers man   I really love this pedal and I will say building the PCB was a breeze, knocking the layout together took an evening, a year ago, before I improved my layout skills (not that they're amazing but still, it can be improved).

Very nice build.

Can someone edumacate me on what an acoustic simulator is?

This uses a simple exciter circuit and a bass boost to get a bit of the boom and crispness of an acoustic.

the concept is something like

The AC-3 is digital (I think?) It's probably closer to the AC-2 build wise (there is a project for this somewhere) but the build is simpler and many say the sound is better but yes, basically, it emulates an Acoustic Guitar!

In practice obviously it doesn't completely capture the sound but in a band situation, it'd definitley be great for a bit of rhythm acoustic without a guitar change or for an intro. Can't say how much I enjoy this one.

would you consider buying a larger batch down the road, scruffie?  

If someone will front the money (I honestly can't afford it) and if Mark (Mr Hammer) Agrees, i'd be happy for the layout to be available, as it stands now though, there are only 4 of these boards in existance.

cheers guys
looking forward to when I have time to build this - put in the archive for now.

Definitley give it a shot!

Great looking build there dude, would like to hear a clip too.

Thanks   It's not the best i've done but i'm happy she'll hold up, although if anyone has suggestions for graphics (especially those can be done without etching etc.) i'd love to hear them.

I'll see what I can do regards clips... no promises it'll be the best quality though.

Edit: Oh and if people want some of my layouts (all with onboard pots) there's a thread here - http://www.freestompboxes.org/viewtopic.php?f=13&t=13740
(If you can't tell from that and this thread, I like 1590Bs, Batteries & Onboard Pots  )

I did post them all here but they were lost when the forum went down months back.

Is the layout readily available?

4 Layer, not etchable.

But as bangerang points out, there's quite a few PCB layouts for this available.