Double Delay Boards

[hoyager]

Awesome man! is that a gain trim I see for the input level to the v3205's?

Also is it possible to make the minimum rate for the lfo really slow? like < 1hz?

Andy

[madbean]

The gain trim is between the two BBDs to allow for some level adjusting. I added that based on how the DMM is set up...we'll see if it is actually needed. I won't be bread boarding this one since most of the design has already been solidified so it goes straight to building the prototype.

For the LFO, right now I have something close to the existing modulation board, but not quite. I think I will breadboard that up and test it with my regular Aquaboy first to see what kind of range we can get.

[Scruffie]

The gain trim is between the two BBDs to allow for some level adjusting. I added that based on how the DMM is set up...we'll see if it is actually needed. I won't be bread boarding this one since most of the design has already been solidified so it goes straight to building the prototype.

For the LFO, right now I have something close to the existing modulation board, but not quite. I think I will breadboard that up and test it with my regular Aquaboy first to see what kind of range we can get.

The reason there's a gain trim in the DMM though is because there's an extra make up gain stage between them, have you added that here? It is good but not entirely necessary. You shouldn't need to trim anything out if nothing's being made up though.

If you are however adding in the extra opamp gain stage (which I assume by opamp count you are) then did you see Dirk Hendriks notes on the improvements that can be made to this stage? Adding a fixed reference to the gain stage so that the gain trim and bias don't interact to get the best headroom.

http://www.freestompboxes.org/viewtopic.php?f=11&t=4051&p=153820&hilit=Behringer+Vintage+Time+Machine#p153820

At 9V that will help things regarding distortion, every little counts.

[Scruffie]

Awesome man! is that a gain trim I see for the input level to the v3205's?

Also is it possible to make the minimum rate for the lfo really slow? like < 1hz?

Andy

If you want slower rates, increase the LFO cap size with 2 Back to Back Electrolytics (Negatives Joined).

For the LFO, right now I have something close to the existing modulation board, but not quite. I think I will breadboard that up and test it with my regular Aquaboy first to see what kind of range we can get.

If it doesn't work out so well on your regular Aquaboy with this set up, feel free to shoot me the schematic for this with the Dirtbag one and i'll see if I can help out.

[madbean]

Thanks Scruffie. I hope to have a look at it tomorrow. I have sufficient room on the board to do either something LDR or JFET/BiPolar driven. I'll be looking at all options.

[hoyager]

Hey, I might be a bit late buit I just checked out the MXR 117, which seems to have a really smooth and nice lfo driving it, which I imagine would sound amazing on the 'deluxe' aquaboy. Doesn't seem that much more complex than the current lfo judging by the schematic.

[rjkanejr]

Tap Tempo???  PLEASE OH PLEASE - These things need tap tempo with an external jack that can throw the clock out to other pedals - for example, it woudl be cool to use one tap tempo pedal to tap the tempo for the delay and have that also sent to the tap tempo tremolo or modified line 6 DL4 and set the time for all three pedals.  I am not a mad genius like the Bean and some of you all here, but I was reading the specs on the LFO chip that musicpcb sells for their tape tempo tremolo and it appears that it can be used for tap tempo on the echo base.  Is that possible and could that same chip or similar method be used here?

[jkokura]

That chip can be used on the LFO of the echobase - the modulation, not the delay.

Your idea about a universal tap tempo is a good one, and theoretically possible, however it is very, very challenging to try and make happen, especially for analog delay like this one. For example, head over to Diamond's website and take a look at the guts of the Memory Lane 1 and 2. see how complicated that is? I don't mean to offend, but it's not so simple to just 'throw it in'. I really suggest you research a bit more about tap tempo DIY.

Tap tempo is neither easy nor readily avaiable, and there is no current and readily available project to apply that would come even close to what you are suggesting. Perhaps one might turn up however. There has been a taptation product available for quite a while that I am looking into for applying it's use in a PT2399 delay, but thats been a slow process for me. It won't be external in my application, nor will it be useable with any other pedals than a rebote type delay.

One company you might want to take a look at is Cusack. They have a number of products that are tap tempo ready and can be universally controlled. You could also go with a midi controlled rack setup, or with a couple of the Eventide 'factor' pedals.

Jacob

[rjkanejr]

No offense taken, and as I said, I am no electronics genius.  No offense to you, but I do kind of take offense to you RTFM comment.  I have been reading, but unfortunately have not been able to locate any pertinent information or anyone that has actually built a tap tempo delay (although it appears Brian built an Echo Base with a taptation once - check out the build reports) or I would have built my own at this point, which is why I posted the reply.  I understand that it is difficult because it seems that very few people have accomplished it except by using digital and COSM type effects/chips.  If I had all the money in the world I would by the Space Echo and TimeFactor and use the MIDI to sync the tap (a friend of mine uses this setup and it sounds incredible) but alas I can't just pull $800-$1000 out of my arse.  Again - no offense.  It seems to me that one of the reasons that people DIY is because it is cheaper, it is a challenge, one can customize, and it is most satisfying to use something that one created himself/herself.  With my non-genious grey matter, it just seems that it should be possible, but apparently it is more difficult than I think it is.  Which is why you guys design and I build and ask stupid questions I guess?

[jkokura]

I'm not sure what RTFM means exactly, but if you're meaning my comment about reading up more about Tap Tempo, I meant more that I encouraged you to start exploring and learning how to do it. You've stated that you don't know much, I meant that perhaps you could start looking into it for us and letting us know perhaps what kind of ideas you might have on making something work! I was trying to be encouraging, not criticizing.

Again, not meaning to offend. My point was simply to suggest that it's a bigger job than we're up to at this point.

Here's what I'm thinking though. I'm going to be looking seriously at the taptation circuit during the next month. Perhaps I'll be able to put out a layout that includes a Rebote and Taptation on one board. From there we might look at how to apply the taptation to a tremolo, or other type of pedal. I can't make any promises, but if you'd like to help out with prototyping and even brainstorming about the pedal functions, perhaps we can start a new thread. I would appreciate the help.

Jacob

[rjkanejr]

Sorry - I am so used to people criticizing (work) that I took your comments negatively.  I should know better as everyone here on this forum has been so helpful.  This really is a great forum and community.  I would love to help in my limited capacity.  I am about to build a tap tremolo for a friend so that may help learn me a bit.  I would love to see tap tempo in a pedal available here, or through some other DIY forum.  My thinking is that it would be great to see interoperability between store bought and home made pedals.  I know that there are mods for other delay units, particularly the DL4 that  allows for external tap tempo with an out jack that passes the tap to another pedal.  It would be great to be able to build a pedal from MadBean or other DIY sources and be able to use it in conjunction with other pedals, say the tape trem, DL4 and the Dirtbag delay.  I did look at the Diamond and it looks like they are using the same chips that Brian is using for the Dirtbag comign soon.  The Diamond has tap tempo (at least for one of teh delays) so I am thinking that either there is tap tempo in Brian's design or it is possible.

[gtr2]

This is an area I am interested in as well but like Jacob said, it just isn't as easy.  Being around here for quite a while, I don't ever recall a situation or question being in the tone of "RTFM"  I had to wiki it.  I figured it wasn't "Ray Tracing Figure of Merit"  I've seen that attitude on other forums but not here.  Which is why I stick around.     We are glad you're here 

The similar chips in the Memory Lane and the Dirtbag only relate to the mn3005's BBD's, not any additional tap tempo circuitry.  I have no idea how tap tempo is done with BBD's but there is most likely a digital controller/digital potentiometer of some sort.  Something I have no knowledge of and it has a steep learning curve compared to analog stuff IMO.  Maybe one day...we can hope, right 

Josh

[Scruffie]

Hey Brian, Did you get anywhere with this idea in the end?

[madbean]

I've got the prototype board on the bench waiting for me. It'll be several days before I can do it....gotta finish these documents first. But, yeah, I am totally stoked to build it up.

[madbean]

Built the prototype today. It's about 90% there. I'm going to tweak the compander a bit and the modulation.

Scruff-you were right about the little extra gain stage I put between the two BBDs. It is not needed.