Boss ds-1 replacement op amp

[TimWaldvogel]

Is there any other designs based on this op amp? Had anybody ever designed something based off this op amp? Is it worth it? Is just a SIL version of any other op amp? Tell me what you know, It would be extremely helpful. 

[blueduck577]

couldn't tell you much about the specific op-amp in the DS-1, but i'll tell you this:  a lot of the time the specific op-amp doesnt matter.  it's the circuitry around it 

[flintstoned]

Mines a M5223AL, but smallbear has a replacment for the ds1, a TA7136. I was gonna order one from them yesterday and they are sold out. Looking to repair my ds1. From what I've researched, using the sil 4558 sounds like crap in the ds1, so they must not be very similar chips. But like blueduck said, its probably due to the circuits engineering. Thanks for starting this thread cause I too am looking for more info on this chip as I would like to find an equivalent/better/cheaper chip to replace it with.

[zombiwoof]

You would have to rewire the pedal to use the Toshiba TA7136, as it has a different pinout from all the other chips that were later used in the DS-1.  It's a 7-pin chip, all others are 8-pin.  If I were you, I'd look to other mods if you want something different out of it.  There were some great "MIJ" mods posted here a while back, try searching for them.  They change other components to get closer to the MIJ sound, and he gives other options for modding for different sounds.

Al

[zombiwoof]

This thread has a link to the document download (it's not just for building a DS-1, there are mods included):

http://www.diystompboxes.com/smfforum/index.php?topic=76021.0

Al

[flintstoned]

Thanks for the info al. I didn't realize that smallbear chip was for the mij version, just assumed it covered all the bases. Saved me a headache or two! Will definitely try out those mij mods down the road.

[Electron Tornado]

The 4558 sounds good to me - but only when the drive is cranked to 11. Back off, especially past the mid point, and it starts to sound bad. Smallbear advertised a replacement for the 5223AL (don't recall the number) and it didn't sound that great to my ears. I did find a place in Britain that was selling 5223's through ebay, so I bought a couple, but haven't had time to test one in a DS-1 yet.

[flintstoned]

Well I did find on smallbear they have a 4560 and a 5218 that appear to have the same pinouts but other than that I don't know squat about them. I did find out today that the ds1 chip is similar to a dual 741 aka 1458 and I do have a handful of those. Maybe I'll try to make the sip to dip convertor and see how that sounds first cause those other two chips are kinda pricey when your not sure if you can use them here. Maybe first I'll just get some scissors and cut the 1458dip in half

[zombiwoof]

Check this out if you haven't already, it will tell you just about everything about the different chips that were used in the DS-1:

http://www.bossarea.com/loadpage.asp?file=boxes/ds1.xml

Actually, there is one other chip that they are using currently in the DS-1 that wasn't listed, the NJM3404AL.  It's been in there the last few years.  Any of those other chips listed other than the 7136P will go right in a DS-1 that had the 5223AL in it, and Small Bear sells some of those.  And I think any of those chips are lower noise and better specs than the 741/1448.  Even without doing the converter board there are SIL opamp options for the pedal.  Out of all the stock chips used in the DS-1, I think the 5223AL sounded a little more buzzy and higher gain, but that was just my impression.  The TA7136P pedals supposedly sound the best, and the rest sound pretty much the same.

The SIL 5218 chip that Small Bear sells was used in another Boss pedal, I think it was the DS-2.  Whichever one it was it was a very high gain pedal (similar to the Big Muff Pi).  I don't know how it would sound in a DS-1.

Al

[flintstoned]

heres a good link too, check out the spreadsheet near the bottom:

http://www.bossarea.com/forum/topic.asp?TOPIC_ID=2181&whichpage=2

i couldnt find the 3404 at smallbear, maybe they dont carry it anymore? i did see a 3403 quad but not a 3404.

[R.G.]

couldn't tell you much about the specific op-amp in the DS-1, but i'll tell you this:  a lot of the time the specific op-amp doesnt matter.  it's the circuitry around it 

Let me amplify (!?) on that. 

The whole reason for opamps' existence is to as much as is humanly possible, make the opamp NOT matter. The whole point of an opamp is that it should not matter. Really smart guys spend their whole professional careers as trained EEs trying to make this be true.

In semi-blind testing, professional musicians have difficulty telling one opamp from the other in the same circuit.

[Paul Marossy]

The whole reason for opamps' existence is to as much as is humanly possible, make the opamp NOT matter. The whole point of an opamp is that it should not matter. Really smart guys spend their whole professional careers as trained EEs trying to make this be true.

In semi-blind testing, professional musicians have difficulty telling one opamp from the other in the same circuit.

And yet, there are people who will argue with you that they can clearly hear the difference between this blah blah opamp and that blah blah opamp. The RAT is the only pedal I have ever seen where this can be true.

The only way I personally can tell any differences between opamps is to look at the waveforms on a scope. I can see some differences, but I can't really hear any.

[zombiwoof]

heres a good link too, check out the spreadsheet near the bottom:

http://www.bossarea.com/forum/topic.asp?TOPIC_ID=2181&whichpage=2

i couldnt find the 3404 at smallbear, maybe they dont carry it anymore? i did see a 3403 quad but not a 3404.

You're right, I just checked.  I would say the drop-in replacements that might work that SB has are the Rohm BA4560 (check the pinout to be sure), the JRC 4558L, and the M5218L.  I don't have any experience with any of those chips in a DS-1, though, as they were never used in a stock DS-1.  I have read of guys putting the JRC4558L in there, and some liked it, and some said it made it sort of generic sounding.  You could get a few different IC's and try them in a socket if you want to experiment.  Or you could find the NJM3404AL somewhere else.  Of course you could also get that conversion board that allows you to use a DIP8 chip in place of the inline chip, and then you could try just about any of the common chips that people use in distortions.

Al

[Ben N]

couldn't tell you much about the specific op-amp in the DS-1, but i'll tell you this:  a lot of the time the specific op-amp doesnt matter.  it's the circuitry around it 

Let me amplify (!?) on that. 

The whole reason for opamps' existence is to as much as is humanly possible, make the opamp NOT matter. The whole point of an opamp is that it should not matter. Really smart guys spend their whole professional careers as trained EEs trying to make this be true.

In semi-blind testing, professional musicians have difficulty telling one opamp from the other in the same circuit.

If this were as true in practice as in aspiration, there wouldn't be many different opamps on the market, just the one "perfect" one. And yet there are, and they vary in measurable ways. I understand that in many applications, a wide range of opamps will work without substantial variation in how they work. But there must certainly be others where the variations between opamp types & specs does matter.

[Paul Marossy]

If this were as true in practice as in aspiration, there wouldn't be many different opamps on the market, just the one "perfect" one. And yet there are, and they vary in measurable ways. I understand that in many applications, a wide range of opamps will work without substantial variation in how they work. But there must certainly be others where the variations between opamp types & specs does matter.

I suppose you could also make an argument for audible differences in opamps where the opamp itself is what is doing the clipping in a circuit. FET opamps tend to sound a little better to than the BJT types, less harsh sounding. But even in this case, I don't hear much of a difference between the two, it's very subtle. If I really do hear anything at all, it seems to be in how the high frequencies are handled, which corresponds to what I see on a scope. If it looks very spiky and jagged on the scope, it seems to also sound harsh, too. But it's hard to do this on your own because you see biases what you think you might be hearing.  

[zombiwoof]

Well I did find on smallbear they have a 4560 and a 5218 that appear to have the same pinouts but other than that I don't know squat about them. I did find out today that the ds1 chip is similar to a dual 741 aka 1458 and I do have a handful of those. Maybe I'll try to make the sip to dip convertor and see how that sounds first cause those other two chips are kinda pricey when your not sure if you can use them here. Maybe first I'll just get some scissors and cut the 1458dip in half

I was just looking at some Boss schematics at Schematic Heaven, and I noticed that the M5218AL is used in the OD-3.  It also was used in an earlier Boss distortion, the PW-2 Power Driver (which was similar to a Big Muff).  It does have the same pinout as most of the chips used in the DS-1 over the years (except for the 7-pin Toshiba chip used in the Japanese and early Taiwan DS-1's).

Al

[flintstoned]

Thanks Al! You da man!

[zombiwoof]

Funny thing, I just picked up a Boss DS-2 (Dual Overdrive, switchable between an overdrive and a higher gain distortion sound, also has a remote jack for remote switching), and I found the schematic for it.  Guess what the chip is?.  M5218AL!.  So I guess Boss used that in a few pedals.  Considering how this thing sounds (pretty good!), I'd say it's worth a try in the DS-1.  I've got several DS-1's myself (it's a long story), so I'm thinking of trying one of those chips in the one I'm going to mod.

All

[TimWaldvogel]

truthfully i was think asboutbuying the sil op amp and designing something around it. SIL op amps honestly seem easier to work with in most cases. i have difficulty designing around dual op amps. this crunch box project is killing trying to design a perfboaard layout

[Paul Marossy]

i have difficulty designing around dual op amps.

One word: "jumpers"