Boss Dd-3 Ic

[Andy S.]

Folks,

I have a DD-3 that passes the signal through ok, but no delay effect what-so-ever. I've checked the PS (battery) and on most components that I can get to or can figure out pin-outs, I get 8.x volts or 5.0 volts where I need it.

However, there is a chip on the board and the schematic that is a bit weird. As far as markings & documentation. The chip marked IC4, a 4066, on the schematic, is showing pin 8 as ground and pin 8 as 5 volts. BUT!!! When you look at the actual chip, there's only 14 pins!!

Add to that, I cannot find a data sheet for it anywhere. The part number 4066 for NTE is some sort of Darlington power IC. If I type in 4066BP, all I get is the number NTE4066B, but no data sheet. So, even though it's a different NTE number I don't know if it's the replacement configuration I need.

Anyhow, I think that device is part of the problem since I either get nothing on some pins or 4.x volts on other pins.

The chip itself has "HD 1 4066BP" on it.

So if anyone has any info on this device, I would appreciate a bump in that direction.

Much appreciated in advance!

Andy S.

[dumbassbob]

DD3 problem

Try going to www.bossarea.com that forum might get you a answer you will have to sign in

[Enzo]

You didn't google HD14066, did you? Data sheet is the first thing that comes up.

In any case, a 4066 is just a CMOS logic chip. Specifically it is a quad bilateral switch. SImilar to a 4016. It has four sections, each acts like a relay more or less. It is used to turn signal paths on and off.

Try also CD4066, MC14066, and many other variations.

SChematic is wrong. It is a 14 pin chip, with power to pin 14, not "16." Pin 7 is grounded, not 8. The four sections within the schematic look right, at least without me digging out the data sheet myself. Just the power connections on the edge of the drawign are wrong.

NTE4066B looks to me like the proper IC, though I do not use NTE stuff in my shop.

Pins 5,6,12,13 are control inputs to the chip. Depending if they want a gate on or off, the control will sit at logic high or logic low - +5 or ground essentially. All the control pins are wired together in this circuit, so all four gates turn off or on at the same time. WHen there is +5 at the control pins, then the gates are on and a low resistance will be between the in and out terminals. SO signal will pass through them.

If the gates are working, when +5 - or anything over about 3.5 really - is on the control pins, then whatever signal is on one side of the gate should appear on the other. Note that you usually cannot read a signal at the input pins of op amps, so pins 2,3 of the 4066 might not read, but there should be signal at the out of IC3 there is the signal is present at the input.

[Andy S.]

You didn't google HD14066, did you? Data sheet is the first thing that comes up.

Yeh, but all I kept getting was sites that just had a huge long list of parts, or RFQ forms. Maybe my computer has an attitude this week?

NTE4066B looks to me like the proper IC, though I do not use NTE stuff in my shop.

Any particular reason no NTE stuff?? I'm still just getting geared up and somehow that was a cross reference site that kept popping up. Also, one of the local small shops where I get parts in small quantities without hassles deals a lot of NTE stuff, so, I go with the flow. I can stop in there and pick up stuff on the way to my accounts for the day job.

Anyway, on the output, no, no signal. That's what I was leaning toward.

You guys are great!! Much appreciated!

[Enzo]

I don't like NTE for a variety of reasons. I run a repair shop, and I find the real parts are usually a lot cheaper than the NTE. NTE parts are not exactly the original, they are instead whatever NTE makes that is the closest fit. I prefer to use the part that belongs there, not an approximation. Price out an MJ15024 power transistor and something small like MPSA06 or 2N3904. Now price out the NTE equivalent. Quite a lot more to pay just to get a poly bag around the part.

TV repair guys like NTE because they can go to one source and stock one line, and come fairly close to most parts. When I have a 1000 watt power amp here, and I have some of the output transistors blown, I do not want to mix the NTE and the Motorola - or Sanken, or whatever - because they were not made on the same line, of the same material, by the same process. So chances are real good they will not share current well. The NTE parts will either turn on sooner, meaning they will hog current and try to do the job without the rest of th parts - so POOF. Or they will turn on later, and so they might asd well not even be there, adn ther rest of the parts have to take up the slack - POOF.

NTE will about always pop up in a search for a part, since so many places carry the line. McDonalds will pop up in a search for hamburgers a lot more often than some place that sells good ones.

Look up 4066 CMOS at Mouser, Jameco, most any parts palace. About 30-40 cents each.

31 cents at Mouser, the NTE version? $1.72 at Mouser. At MCM, just looking for 4066 brings up the right part, they want 62 cents. MCM has the NTE4066 at a bargain $1.62.

Make sure the letters on the end work, you want to get the chip in a DIP, NOT surface mount.

[Andy S.]

I don't like NTE for a variety of reasons. .........When I have a 1000 watt power amp here, and I have some of the output transistors blown, I do not want to mix the NTE and the Motorola - or Sanken, or whatever - because they were not made on the same line, of the same material, by the same process. So chances are real good they will not share current well. The NTE parts will either turn on sooner, meaning they will hog current and try to do the job without the rest of th parts - so POOF. Or they will turn on later, and so they might as well not even be there, and the rest of the parts have to take up the slack - POOF.
.........

Years ago when I worked for Newcome Sound in Columbus, we had a rig set up to check for gain on the replacement transistors we got from two manufacturers. When we did upgrades or repairs, we always tried to have Xsitors that were matched as close as possible.



I need to keep that in mind as the GK 800RB I'm working on might have a problem with the output transistors. So far, the only stuff I've completed are low output guitar amps with broken leads or one bad transistor. Nothing to match up. I'm still working on the Johnson JM-150! That may need matched items.

Thanks for the info on Mouser. I've bookmarked it for future use.
As for the local convenience, One of the bigger parts suppliers seems to really shun and discourage the small repair business.

Thanks again!
Andy

[Enzo]

In a high power amp, it is not just gain. it is important that the transistors track thermally - all heat and cool at the same rate - and even teh speed of the transistor can matter. How fast can it turn off when base drive is removed?