I just built the florist. Everything works correctly, but I have hiss at volumes above the half way point. Louder volume, louder hiss. Also, unity volume doesn't happen until around 4 o'clock on the pot. I can deal with the volume, but the hiss is too much. Maybe the PT2399 or 2n5457? Going to try swapping them out and reflowing all the solder joints. Anybody have any ideas before I dive into it? thanks
Do you have hiss when the Blend pot is full CCW? IOW, when it's just dry signal.
Usual suspects of reflow and check parts values. I believe mine was a tad hissy but no more than a standard PT build. I'd be suspect of the chip as well. But especially if you're getting hiss at the dry side I'd supect a part value.
I reflowed everything and changed all the chips. Values are definitely correct for everything. I suspect the 2n5457 may be fake or really out of spec. Ordered new genuine ones from GuitarPCB that are hand tested. I only get hiss when blend is above 2:00 and volume is also above 2:00 (very little at this point and louder as these controls are increased). It isn't affected by any other controls. The volume and blend both share the part of the circuit with the TL072 (which I swapped and no change) and the 2n5457. I'm thinking this might also be the reason why I don't reach unity volume until about 4:00 on the pot. (low gain/out of spec 2n5457?) thanks
It sounds more like the hiss is coming from the PT2399. You could just have a noisy one, so if you have it socketed maybe try a couple different ones if you have them on hand. The 2n5457 is just a unity gain buffer. But, you could audio probe the gate and source pins to see if you have about the same volume level on each.
The effect itself isn't meant to offer a large signal boost so achieving unity higher on the control doesn't necessarily mean there's an issue there. You can swap out the Vol pot for a linear tape to move unity further back though.
So, my recommendation is use an audio probe if you have one. Check the input and output of Q2. Also, check pins 16 (input) and 14 (output) of IC2 to see if either of those are the hiss source. If so, swap the PT2399. If that doesn't help you can increase C9 to 3n3 and C12 to 22n to dampen the noise a bit. The design is light on the filtering but since the delay time is so short in this effect (to achieve chorus) it shouldn't need nearly as much as a full featured delay.
I did swap the PT2399 (everything is socketed) and that didn't help but I have one more to try. I'm going to try one of the J201s I have temporarily just for the heck of it in Q2 while waiting for more 2n5457s. I don't have an audio probe (just a dmm and o-scope). Then I think I'll double check all the values again for sanity before swapping c9 and c12. thanks for the help
I was wrong. I do have a small amount of hiss when blend is fully CCW. I just didn't have the volume high enough to hear it.
I just tried 5 different PT2399s, including 3 out of pedals that are working fine (admittedly, these are probably from the same vendor, Tayda, but from multiple years). Also swapped in a J201 to try. nothing changed. I have a lot of hiss, actually now that I put the knobs on the pedal, I can see that I have hiss at all positions of the blend (more as it increases, or volume increases). I guess I'll go through the whole board again and recheck component values. I haven't made a mistake with them in all my years of building pedals but there's always a first time.
Okay, let's try this: pull the PT2399 out completely. Now listen again with the Blend pot full CCW. Is the hiss still there? What about when you start turning the Blend pot up?
With no PT2399, I have some hiss, seems to be less but definitely still there. It is there with blend fully CCW and does not change at any position of the pot.
I have C25 backward. I'm looking at it while on a work meeting. Will change at lunch today and try again.
I installed a new cap in C25. it took care of the low volume problem, but I still have hiss. without the PT2399, it's very low. As soon as I put in the PT2399, it's amplified exponentially. I tried 4 of them. All the same result. I'll go through all the components again against the schematic. Almost ready to scrap this one, order a new board, and put a new one together. This one's giving me fits. I just did 4 builds and this is the only one causing me issues. I swapped the other chips and put a J201 in place of the 2n5457. None of them made a difference. (I didn't expect them to)
Where did you get your PT2399 from?
I've gotten them all from Tayda over the years. I took ones out of other pedals that are working. I've got low level hiss without the chip in there. But I do have a low level hiss in one of the other delay pedals that uses two (but it's very low with both of them). I made that pedal years ago. I tried those in this pedal and same hiss. The hiss in the other pedal is low when they are installed. The florist is low when it's not installed and then loud with it in there.
I just went through and verified all my component values against the schematic and they are correct; however, I do have different values for the led resistors (10k for R35 and 1k for R32). I can't imagine this would cause hiss.
Sounds like it's time for an audio probe.
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Just ordered another board. Gonna give it another go. I really really appreciate all the help with this.
Before you start building another one, let's see if we can make some headway here. A couple more notes:
Like Jimi said, and audio probe would help a lot here. You don't need to fabricate one. You just need a foot of wire and a 100n cap. If you need more guidance on how to use it we can certainly give you some tips.
The other thing is it is possible the PT2399 is the main culprit. It may produce less noise in other circuits you have tested with the ones you have, but those circuits are likely to have much heavier filtering as is required for delays, etc. Tayda is an okay source for some things, but occasionally we do see problems here with active parts sourced from them.
But, since you've ordered another board, let me dig through my stash and pull out a PT2399 I know is good. I'll send that along with your order so you will at least have something to compare to. I don't recall my Florist being particularly noisy but I'll fire mine up just in case so we have a baseline.
I appreciate it, but troubleshooting this one has honestly worn me out. So I ordered the new one today. After reflowing the points several times (and maybe cooking a component?), verifying all the values against the schematic, changing chips and transistors multiple times, I just need to throw in the towel on this board and build a new one. I have no doubt it’s an issue I created (maybe I need to not build when I’m really tired) but I haven’t had this much frustration with a build in years. I did also order 5 PT2399s from GuitarPCB that are guaranteed to be factory direct and genuine. I’m sure the rebuild will be fine. I’ve built several of your boards over the years and have never had a problem. Again, I do appreciate all the help.
No worries. But, I'm still sending you another PT2399. Believe me, the point you are at I have been myself many times. I completely get the frustration.
thanks. I have to order some of the parts for the rebuild, and I'm away on vacation next week. So this will likely be in a couple of weeks. I'll check back to let you know how it goes.
I checked into this today and I was able to reproduce the hiss you are talking about. The good news is it definitely comes down to the PT2399. I have two different batches. One that I bought from smallbear and another I bought cheaply (years ago before Tayda was even a thing). The smallbear one worked perfectly with only a minor amount of expected noise (minimal). The other batch were awful. Lots of hiss and lfo noise. So, those were clearly out of spec. I'll probably end up tossing those altogether.
Bad news is I don't have any spares from the smallbear batch that I can send you. So I suggest getting one from them or maybe stompboxparts. I believe that will solve your issue. I'll add a note to the build doc summarizing this info.
I had the same issue on a little angel chorus with Tayda pt2399s. Out of a dozen of them, only 3 wouldn't latch up when you gave them juice and they were noisy as hell. I will also add that Amplified Parts seems to be a good source for pt2399 chips. I bought half a dozen from them and they were all good with minimal noise.
I've had bad hiss issues with only a few PT's out of a fair number so I'd consider myself lucky. Sucks having to start from scratch but sometimes you just troubleshoot a board to death and it's time to start fresh. My worst was the Collosalus flanger and by the time I had a handful of jumpers to make up for scorched pads I threw in the towel. Good news is the second time around fired right up. I always meant to go bad and do a post-mortem but in the end tossed it.
Another option, and imo a better choice for chorus circuits, is the HT8970. I've been using those in place of the 2399s in most of my recent builds, and have to have an issue. Of I get a moment later, I'll whip up a demo comparing a PT Florist and HT Florist
thanks for all the replies. I did confirm that most of the noise is most likely coming from the PT2399 and the board is probably built correctly. I was running this board in the loop of a new amp (Orange TH30) that I just received. It is a 12at7 tube driven loop, and the loop itself has a tiny amount of hiss (confirmed this by running a direct cable from send to return) that is being magnified by the PT2399 along with whatever noise it's producing. I moved the pedal over to my H&K pedal board and it's much quieter. Both power supplies are fully isolated, but swapped it between then to rule out power issues. Still has some hiss above about noon on the volume and with blend also above noon. I have 5 new chips coming this week from PedalPCB, who guarantees they are genuine and factory direct. Cross my fingers that at least one of them is quieter. gotta grab a new 12at7 for the loop on this amp too (only type I don't currently have on hand)
It could be that the th30 effects loop is noisy. I have an orange OR15, and I stopped using the loop entirely because of a ground loop issue that makes a lot of noise. With no effects hooked up and just a cable plugged into the return jack, the amp makes more hiss than I can tolerate. I also have a rockerverb 100 mkiii that doesn't suffer the same issue
Quieter PT2399 was the ticket. Just a little hiss at the higher blend and volume, but overall sounds great. I didn't build the new board. Using the existing one. Thanks for all the help!