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Messages - Max

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1
Open Discussion / Re: Music theory recommendations?
« on: May 28, 2020, 12:41:27 AM »
Rick Beato, has a lot of content on youtube (not only about theory) and a also a text book.

2
General Questions / Re: J113 for phasers
« on: April 27, 2020, 01:23:44 AM »
I have no experience with phasers in general, but I have a bunch of J113 unused, so this is interesting...
I would say that the use of the transistors in a phaser is very different from a distortion pedal, so in terms of sound is not so critical, given that they are properly matched.
Please correct me if this is just gibberish  ;D
Actually, I was planning to use the J113 in the switching part of an echo project, they shouldn't really make any difference there, but I have enough for a little phaser ;)

EDIT: I just checked the schematic with a phase45 and they are really close, there's only a couple of resistors different (and the fets and op-amp of course).

3
General Questions / Re: Repairing a Pride of Texas
« on: April 26, 2020, 01:29:14 AM »
Yep, they are scary as hell at first, but after a while I'm starting to like them. After the Orange MkII circuit I'm drawing all my jfet based boards with smds. OK, it started out of necessity, but now it's making things more interesting.

4
General Questions / Re: Repairing a Pride of Texas
« on: April 17, 2020, 10:04:16 AM »
Great, perfect, thank you very much, now I can try to find it somewhere (hopefully I won't have to buy a bunch of 10 or 100).
So this topic is heading toward a happy ending (thanks to aion  ;) )

Cheers,
Max.

5
General Questions / Re: Repairing a Pride of Texas
« on: April 17, 2020, 07:19:10 AM »
Third (!? maybe) update and advice request.
I found the culprit: it's the zener marked as Z1 and shown in the picture below. Once removed everything works like a charm  8)
First I tried to power the effect board on it's own, just to realise that part of the in-out circuitry is in the switching board, so I built a veroboard with the same parts I was lucky enough to have lying around and found that the effect works perfectly. Then I went on and removed Z1 from the switching board, and found it is shorted in both directions.
Now, the circuit works perfectly without Z1, would you suggest to leave it out or look for a replacement?
Consider that:
a) I have no idea of what kind of zener that is, and is bigger (in size) than anything I've found so far.
b) I'll most likely sell the effect


6
General Questions / Re: Any tips on de-soldering a 10 pin relay?
« on: April 13, 2020, 02:31:22 AM »
At work, in an old drawer, I found something like this:

Not exactly the same, the tip is almost identical, but it's attached to a simple shaft that I can attached to this:

Which is a bit oversized, but works great to remove IC sockets, relays and everything with more than two pins. Not for stomp switches, however.
Unfortunately it's very oxidized and not that effective anymore, and I can't find a cheap replacement  :'( :'( :'(

7
General Questions / Re: Repairing a Pride of Texas
« on: April 12, 2020, 05:53:04 AM »
Easter update: I (carefully) removed the reverse polarity protection diode and separated the two boards. Well, the diode is fine and the short is still there, so I traced the whole board and found two possible places for a short, the 7550 voltage regulator and the zener Z1. Hope it's the zener...
Anyway, here's the schematic. I still have a big ? about the microprocessor, I couldn't find any information online, but the pins' function is pretty obvious, now. Also the capacitors (except for the electrolytics) will have to be guessed, though I expect the usual suspects.
I think I'll try to power up the effect board alone to see if that works.

8
General Questions / Re: Repairing a Pride of Texas
« on: April 08, 2020, 08:11:13 AM »
Bad news, maybe it's fault of my cheap scope, but I can't see any signal on the solenoid's pins.
I can try and troubleshoot the switching board, but it would be definitely easier to replace it with something like the nope relay bypass.
I may also design a new pcb to replace the original one.
Mmmh, need to mull it over  :-\ :-\
EDIT: of course I couldn't see anything, the +V on the DC input is short to GND  :o :o
Now, with all the smd parts good luck to me in finding where the short is... I need to identify the reverse voltage protection diode.

9
General Questions / Re: Repairing a Pride of Texas
« on: April 06, 2020, 10:02:05 AM »
Thanks, that makes sense, I'll check with my scope. So it's still possible that the relay is the culprit.
Actually, it wouldn't be difficult to replace it with a 3pdt, if it weren't for the space inside the enclosure. I'll check, but it doesn't look high enough for a mechanical switch.

10
General Questions / Re: Repairing a Pride of Texas
« on: April 06, 2020, 05:48:18 AM »
Update 1: I checked the switching board, the resistance across the relay's solenoid looks fine, but I can't read any voltage when pressing the foot-switch. It's a latching relay, so I expect a voltage only when the foot-switch is activated, +5V set and -5V reset. On the other hand, also applying 5V directly to the solenoid doesn't have any effect, so I'm a bit puzzled.
There is a strange IC on the switching board, I can't find any information on the internet. It reads F1102AMB 1741N, any idea?

This is going to be tricky...
 :(

11
Open Discussion / Re: Best substitute for j201
« on: April 04, 2020, 05:58:13 AM »
I also managed with a normal iron to solder some of them, it's a bit tricky but doable. It would be better to use solder paste, but flux with normal tin will work just fine.
I've seen the J113 mentioned as substitutes, but a quick look at the datasheet suggests otherwise. I have some of them, but never tried to swap them with J201.
All in all, considered the variation of characteristics among jfets, probably you should just get a bunch of other transistors and test them. You should do it anyhow with the J201s. Once I needed 3 of them, bought 10 and they were all completely out of specs. I had to order ten more to find 5 or 6 acceptable.
That's why in my orange MkII build I used the smd version, which is a lot cheaper and has a smaller variation in specs.


12
General Questions / Repairing a Pride of Texas
« on: April 04, 2020, 05:07:18 AM »
I just put my hands on a broken Danelectro Pride of Texas. Honestly, I was hoping for something easier to repair. Damn it, this thing is all smd, also tracing it (  ;) ) will be a nightmare. However, it looks like the problem is on the switching board, so hopefully it is the relay that's faulty.
More to come when I have time to work on it...
PS: according to a couple of stickers on the box (that were casually covered by some white labels...) this was already on offer on Amazon as reconditioned.

EDIT: I just realised that probably I picked the wrong forum for this thread, if anyone reckons appropriate to move it somewhere else please go ahead.

13
Build Reports / Re: Pedalboard pics megathread
« on: March 23, 2020, 01:46:00 AM »
Thanks, yes, indeed it is quite light, but it's very solid, you can step on it. Well, at least I can, but I'm not exactly what you would call a big guy  ;D And with the velcro I can move it around without worrying about stuff flying off the board.

@Playpunk: your link is broken!

14
Build Reports / Re: Pedalboard pics megathread
« on: March 22, 2020, 06:54:40 AM »
Here's the pedal board I made some time ago (things that happen when I'm home alone). I used some alluminium profiles and some scrap wood I had at home. The wood has been appropriately beaten up and stained to give it this old barn look, while the screws have been polished to a mirror finish. I like this contrast 8) 8)
The effects are all by me except the EQ and the looper. The power supply is a Harley Benton Powerplant Junior.
The input on the side is stereo and is split in two channels in the board, all because one of my guitars has a stereo output (E pick ups + Piezo).
The piezo channel goes to the EQ while the electric channel goes through the rest of the effects. The little box in the lower left close to the looper (the Switch) is used to switch the output between the two channels and goes directly to the looper.
I'll open a thread with some build reports of the effects in the pictures for the more curious of you  ;), but there's a Skreddy Lunar Module, an MXR Distortion+ slightly modded, a ROG tri-vibe, a 3Verb from Musikding with an added tone control, and the 1590DD in the middle is a ROG Ginger with a modded Condor cab sim, basically an Ampeg Portaflex + cabinet in a box. I use it with a bass, but it sounds good with guitars as well.

15
General Questions / Amp-in-a-pedal and negative feedback
« on: March 14, 2020, 05:09:51 AM »
Hi All, I've had some experience building some distortion pedal derived from famous amps, especially from runoffgroove, and after experimenting with my take on the Orange MkII (check the 2019BOTY contest for more) I'm now trying to understand a bit more about the negative feedback.
From what I get, this is used to bring part of the signal from the output transformer back to the cathode of one of the preamp valves, where the signal phase is opposite w.r.t. the anode, in order (for example) to tame the highs or increase/reduce the distortion.
Now, some of the older projects from runoffgroove (i.e. Professor Tweed, Thunderchief and Flipster) as well as the orange project I started from, follow the original amp schematic 1:1 leaving out the final tubes and the output transformer, but include the negative feedback which, instead of taking the signal from the output transformer, takes it from the output of the pedal, which, correct me if I'm wrong, is equivalent to taking it from the output of the preamp.
My question is: without the output transformer, doesn't the negative feedback just suck signal from the output without really affecting the tone as in a real amp? Maybe this is one of the reasons runoffgroove moved away from this 1:1 philosophy to get better sounding circuits in terms of fidelity to the inspiring amp.
EDIT:
this is probably the best explanation I've seen of the negative feedback:
https://youtu.be/H5fFb5_9xyA?list=PLhv-fcfLlQdrnP4wn5wWaaO8_Y8IFrPxx

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