Dirtbag Deluxe 3?

[agoldoor]

And is there any reason to test MN3005 (or rather, are you planning on it?)

[madbean]

When you run at 12V with 10V on the BBDs, what voltage do you have the clock at? It should be the same voltage as the BBDs. Also, regards the clock buffer, how do you have the inverters set up? In this case I would think all 3 in parallel would be the better choice over the standard flanger 1 in to 2.

The BBD and clock are on separate but identical power rails (10v). So, they are isolated from the audio power and from each other. I considered doing a separate regulator for the two but the routing is proving to be a bit too much for it. I may even try a 15v audio and 10v BBD (like the Echoczar) for giggles. The inverters are set up like the flanger type, but I can always try it the other wire with the breadboard.

[knauerj]

So 4x3005 gets 1100ms.... Just need tap tempo now

I got this on standby
http://www.smallbearelec.com/servlet/Detail?no=1334

Interesting....is that going to work with this new version?

[madbean]

I actually have a separate delay design based around the MV-64. I considered it for the Dirt bag but decided against it because of the already high part count.

[Scruffie]

When you run at 12V with 10V on the BBDs, what voltage do you have the clock at? It should be the same voltage as the BBDs. Also, regards the clock buffer, how do you have the inverters set up? In this case I would think all 3 in parallel would be the better choice over the standard flanger 1 in to 2.

The BBD and clock are on separate but identical power rails (10v). So, they are isolated from the audio power and from each other. I considered doing a separate regulator for the two but the routing is proving to be a bit too much for it. I may even try a 15v audio and 10v BBD (like the Echoczar) for giggles. The inverters are set up like the flanger type, but I can always try it the other wire with the breadboard.

Hmm, well I don't know exactly what you're doing so this may be moot but power filtering wise, you may find that it's better to run the clock/lfo directly off the regulator and then use r/c filters for everything else to separate them. Anyway, only mentioned the clock/bbd voltage cause of your distortion but seems that it's not the issue

The only reason I mention the inverters is when it came to that 1 in to 2 set up, reason was that 3 in parallel over buffered basically but as that was for a single MN3007 being clocked to extremes and here we're going for maximum load with the 4 x 3005, might work better.

[kothoma]

They're back: http://www.ebay.com/itm/MN3008-Original-Panasonic-Matsushita-8P-DIP-IC-2-pcs-/291255711068?

[Govmnt_Lacky]

Snagged a couple. Might build with them. Might hold on as trade bait! Who know?? This is exciting!! 

[lincolnic]

Thanks for the heads up! Jumped on a couple pairs myself.

[aballen]

I just grabbed two pair myself, anyone else find it suspect that the two in the pic are stamped identically?

[madbean]

Hmm, well I don't know exactly what you're doing so this may be moot but power filtering wise, you may find that it's better to run the clock/lfo directly off the regulator and then use r/c filters for everything else to separate them. Anyway, only mentioned the clock/bbd voltage cause of your distortion but seems that it's not the issue

The only reason I mention the inverters is when it came to that 1 in to 2 set up, reason was that 3 in parallel over buffered basically but as that was for a single MN3007 being clocked to extremes and here we're going for maximum load with the 4 x 3005, might work better.

Thanks for the insight, Scruffie. The way the proto was designed I have a master regulator for audio and LFO. The clock and BBD are two separate R/C filtered supplies derived from the regulator. It was only after I thought about trying the BL3208 12v or 15v on audio and 10v on BBD. So, on that one I have two 5.1v Zeners in series on each 10v supply line to the clock and bbd. It seems very stable voltage wise, but it's worth considering two separate regulators perhaps. I mean, you could run the DMM on 18v audio / 15v BBD, too AFAIK. Never tried it.

The distortion issue may just be the chip itself. I'll know more tomorrow when I work on this again.

[Scruffie]

Hmm, well I don't know exactly what you're doing so this may be moot but power filtering wise, you may find that it's better to run the clock/lfo directly off the regulator and then use r/c filters for everything else to separate them. Anyway, only mentioned the clock/bbd voltage cause of your distortion but seems that it's not the issue

The only reason I mention the inverters is when it came to that 1 in to 2 set up, reason was that 3 in parallel over buffered basically but as that was for a single MN3007 being clocked to extremes and here we're going for maximum load with the 4 x 3005, might work better.

Thanks for the insight, Scruffie. The way the proto was designed I have a master regulator for audio and LFO. The clock and BBD are two separate R/C filtered supplies derived from the regulator. It was only after I thought about trying the BL3208 12v or 15v on audio and 10v on BBD. So, on that one I have two 5.1v Zeners in series on each 10v supply line to the clock and bbd. It seems very stable voltage wise, but it's worth considering two separate regulators perhaps. I mean, you could run the DMM on 18v audio / 15v BBD, too AFAIK. Never tried it.

The distortion issue may just be the chip itself. I'll know more tomorrow when I work on this again.

The LFO and Clock should share the same voltage really, if you run the LFO at 15V and the clock at 10V you wont get the same modulation range seeing as the LFO is modulating the clock and it's going to be swinging between a higher voltage.

Hmm... just a small idea but rather than 2 x 5v1 zeners, wouldn't an LED do the job for dropping the voltage down to 10V from the 12V supply? I've given in trusting zeners for anything but very minor current jobs.

I mean 2 regulators would be ideal but not necessarily a requirement. I personally try and avoid r/c filters on clocks due to the high current demands of them, can lead to unexpected behavior, not so bad if the main supply is steady but if using a charge pump.

I guess you could run the DMM on 18/15V I can't see it offering much benefit though, the DMM is already pretty decent audio wise as far as headroom goes and when the BBDs have only 1V P-P or whatever it is.

[Scruffie]

Hang on a minute, have you given the make up gain stages between BBDs a fixed V.Ref and the BBD an independent bias trimmer? If not when you're setting the bias for your 3rd BBD which is at 12V so wants to see 6V bias and the BBD which is at 10V so wants to see around 5V one or the other isn't going to be biased correctly.

[knauerj]

They're back: http://www.ebay.com/itm/MN3008-Original-Panasonic-Matsushita-8P-DIP-IC-2-pcs-/291255711068?

Crap....looks like the listing ended. I shouldn't have dragged my feet.

[lincolnic]

I got my four MN3008s today from our popular eBay seller, but they weren't packaged with any ESD protection. Since the Dirtbag 3 still has yet to be released, I don't have any circuits to test them in. Is there any other way I can check to see if they're working/real?

They also all have the same production code stamped on them, which seems a little suspect. Anyone else who ordered chips from the relisting, how did your chips turn out?

[kothoma]

I got my four MN3008s today from our popular eBay seller, but they weren't packaged with any ESD protection. Since the Dirtbag 3 still has yet to be released, I don't have any circuits to test them in. Is there any other way I can check to see if they're working/real?

Take any MN3007 based chorus and build a little adapter.

They also all have the same production code stamped on them, which seems a little suspect. Anyone else who ordered chips from the relisting, how did your chips turn out?

Wouldn't this be normal if they're from the same batch?