Aquaboy chips

[jkokura]

Hey Brian,

Is there a sonic difference between the MN3005 and the V3205? Both work for the effect, but the cool audio is obviously much cheaper and easier to procure. I've read that the V3205 is darker and not as good sounding though. Can you say whether it would be worth working to ge some mn3005's or if the V3205's can get me into that DMM sound im hoping for?

Jacob

[Micpoc]

You may wish to check out these threads:

http://www.madbeanpedals.com/forum/index.php?topic=133.0

http://www.madbeanpedals.com/forum/index.php?topic=9.0

[gtr2]

I've been looking for MN3005's for a while with no luck.  I'm skeptical of ebay, and an outsourcing company wanted 75 a piece for them.  I wanted the mn3005 for the higher headroom and it was in the original aquapuss.  I might just use the v3205 as I have a double delay board and finding 2 mn3005's may not be possible (cheaply).

Let me know if you find any, I know some others on FS found them at UTsource but they did not respond to my request even for a larger quantity.

[madbean]

I just got a couple in from UT Source. Haven't tested them but I will let you know how it turns out. They have the right packaging, which is good. I also ordered an MN3205 and it looks like it's probably fake.

Anyway, for two MN3005 it was $25/each. For 75, they will probably charge $20.

[jkokura]

Thanks for the responses guys. I appreciate them.

What I'm really looking for is if there's a difference in sound though. If I can get DMM sound out of the v3205s there's no question but a big post on FSB makes me think there is a sound quality difference that makes me think I might take the time to save up for 50 buck chips because I do love the sound of the DMM. Of course, running the aquaboy at 18v might make a difference, but I doubt I'll get a road rage, aquaboy AND the double delay board into a 125B.

So is there a sound difference?

Jacob

[Micpoc]

Of course, running the aquaboy at 18v might make a difference, but I doubt I'll get a road rage, aquaboy AND the double delay board into a 125B.

I'm not sure that the v3205 CAN be run at 18v; Brian may know more about this. 

[madbean]

Based on what others have stated, there is a qualitative difference between using an MN3005 at -15v (as in the DMM) and the v3205. I can't really speak to it because I don't have a DMM (but I do have a clone project in the works). At 9v, like the Aquaboy, I think the difference is minimal based on having built both versions. So I can't say that the expense of the MN3005 is worth it, esp. because they have become so hard to get since the AB board was first released.

You definitely cannot run the Aquaboy at 18v with a v3205 without some modification. And you for sure cannot run it at -15v. While you can supply higher voltages to most of the circuit, the v3205 still needs around 5-7v to operate. You could stick a 5v regulator in there, and the board has space for that. This is exactly what I'm working around with the next delay project: high voltage on the audio and filters to try and comp some of that DMM magic.

Anyway, it just depends on how much expense you are willing to take on in search for the perfect delay. Admittedly, I am pretty pre-occupied with this right now.

[jkokura]

I think I'm pretty sure I'm going to build the V3205 version for my 125B Analog Delay pedal in the works. I was hoping that I could get into the DMM sound without the gigantor box. Perhaps the project in the works will be something I can get excited about also! Look forward to it Brian.

In the meantime - if someone can really compare the sound of the v3205 to the sound of a mn3005 it'd be great info to share with the community. It'd be nice to really know what that extra 40 bucks buys you.

Jacob

[synthcube]

As a result of my plan to have a number of large format Blacet Time Machines professionally assembled, I  searched for sources of obsolete MN3005 BBD (bucket brigade delay) IC. The history of difficulty sourcing these ICs is well- documented in a number of forums:

http://freestompboxes.org/viewtopic.php?f=17&t=8116&p=90518&hilit=mn3005
http://www.diystompboxes.com/smfforum/index.php?action=printpage;topic=95978.0
http://www.madbeanpedals.com/forum/index.php?topic=645.0
http://electro-music.com/forum/post-278819.html
http://www.thegearpage.net/board/archive/index.php/t-1028286.html

Having invested the time to find these ICs in a meaningful quantity, it was important to provide documentation to overcome concerns about the validity of the ICs. We established a simple process for evaluating them:
1)   Buying parts only from suppliers who have a track record of being able to provide genuine MN3005s in the past- no random e-bay buys.  These sources are well-documented in the various forum posts as providing legit MN3005s.  These 'recognized' suppliers act as the first line of defense against fakes. Approximately 3/4 of all orders placed were identified as 'fakes' by the supplier before shipping to me.     
a.   Of eleven 'named' suppliers, seven claimed to have stock of the MN3005, only four actually did.
b.   The average price I paid across 160+ ICs is about $33 per.
2)   Checking each IC against the visual clues that indicate fakes. These are well-documented in various forum posts, and include such items as pin size and length, condition of the top and bottom surfaces, expected logo and date codes, etc. Another good reference is http://www.aeri.com/counterfeits.html
3)   Testing each IC against a reference chip by installing it in a testbed Blacet Time Machine- fully documented in youtube videos -- http://www.youtube.com/watch?v=cD6i3osyfZg

a.   Acoustic test- video documentation of each IC demonstrated from 'no delay' to 'full delay' to compare the sound quality against a reference IC
b.   Scope test- screenshot .jpg files for each IC for 'no delay' and 'full delay' states, to compare against the screenshots for the reference IC- using the Oscium scope app for the iPad
c.   Visual inspection photos- macro-scale photos top and bottom for each IC

ICs that failed are also documented – like this one. Example here : http://www.youtube.com/watch?v=IIV0KsThoRc&feature=youtube_gdata

I find it useful to show how bad chips act, for comparison with the good chips. For those of you who care, the failure rate is about one in thirteen ICs across my sample set of 160+ chips.

Why the Blacet Time Machine?
It's a unique module. Synth designers like Blacet (and others like him) deserve to have their good work recognized. The older parts make it special and unlikely to be replicated.

'Families' of MN3005 BBD IC
From the 160+ ICs I bought, there appear to be three 'families.' I do not have any production documentation from Panasonic nor Matsushita, but the 'families' could relate to different production facilities and/or timeframes.
A)   'Shiny Top' Triangle Logo ICs- these appear to be the oldest ICs. They have a shiny top surface, and the text is faded relative to the other ICs. They do not have the characteristic edge band around the circumference of the top. These ICs' have an indent on the top of the chip that is ABOVE the logo and date code. The bottom indent lacks any text.
B)   'Edge Band' Triangle Logo ICs- these ICs have the visible edge band around the top of the IC and the triangle logo.  These ICs have an indent on the top of the chip that is BELOW the logo and date code. The bottom indent contains some combination of letters and numbers usually two items but sometimes three.
C)   'Circle Logo' ICs- these have the logo described by an 'M' inside of a rounded box and would appear to be the newest of the ICs in this assortment.
When you listen to the videos, and view the scope traces, you'll see very little correlation between the families and their resultant sounds; in other words, they appear to be interchangeable across families.

Disclaimers
I have acted in good faith to buy and test these ICs. I am a hobbyist I did this because I enjoy these devices and helping others enjoy them. I am not an engineer and this is not a full-time job. I cannot guarantee that these are 'genuine'--  only that they work as demonstrated in the videos and pictures. These are electrostatically sensitive devices and although I take ESD precautions, they are subject to damage from static discharge. There is a good reason that highly qualified people like Steve Daniels at smallbearelec.com don't have them anymore. Some of these are NOS and some are pulls, and you can evaluate that based on the photos and documentation. I have invested my own money in buying and testing a bunch of these.

[TNblueshawk]

Wow. Thanks for posting.

[DutchMF]

Jacob, I remember reading a post a while back of someone who built a Dirtbag with MN3205's and was in the process of building another with MN3005's, which might just be the answer to your question on how they compare. The problem is I cannot remember who it was, which might make locating the post a bit easier......

Paul

[jkokura]

Wow... thread resurrection. I'm long past the point of needing an answer, but thanks for those that are chiming in.

Jacob