Florist hiss

[jimilee]

Sounds like it's time for an audio probe.


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[LJangel]

Just ordered another board. Gonna give it another go.  I really really appreciate all the help with this.

[madbean]

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.

[LJangel]

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.

[madbean]

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.

[LJangel]

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.

[madbean]

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.

[blackhatboojum]

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.

[gordo]

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. 

[DGWVI]

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

[LJangel]

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)

[harryklippton]

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

[LJangel]

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!