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Messages - WormBoy

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Great that you managed to solve the problem. I personally make a habit of testing each resistor, each cap, and even each diode, with the DMM before soldering it in. It takes a lot of time, but I just hate debugging and desoldering  8). Once in a while every supplier makes a mistake ...

The C5 is just a coupling cap. I don't expect that anything larger than 1uF will make an audible difference. The MB version probably suggest the 1uF as it is easy to get in a film version (which has a better audio quality that electrolyte caps).

General Questions / Re: Replacing tubes
« on: December 18, 2018, 01:28:56 PM »
that said, vintage amps rarely had bias adjustment (or even matched tubes) so even if you just end up getting a matched set of tubes you're doing just fine.
Those were different times, when tubes were more consistent (and more tubes were thrown away). You may get lucky though. In general, it won’t blow up, but may not sound its best, which is a pity.

So replacing the tubes didn't do the trick. After playing for a solid 15-20 min the amp started to to the exact same thing. Any thoughts? Is it possible that there is a cold solder joint?
Take it to a reputable tech and get it sorted out. Tube amps can kill, so I would not mess too much with it unless you know what you’re doing.

I am assuming that this means I would connect one side to the square pad on a diode pair and the other side to the other square pad on the same paAm I correct in my thinking?
That should work. Generally, the square pad of one diode will be connected to the round pad of the one next to it. However, you can also have a PCB were there are four clipping diodes. So, check the schematic! Usually clipping sections will have one ‘start’ and one ‘finish’ where everything comes together. These are the one you like to use. There will usually be two pads connected together and you can take one of them. I hope that is clear, otherwise let me know  ;D

Don’t jumper diodes, just leave them out if you don’t want to use them. If a distortion circuit has two sets of clipping diodes (hard and soft clipping), you can do whatever you like, including another add on clipping board. The thing to look at is clipping thresholds. If you have silicon diodes in a feedback loop (soft clipping) and LEDs after it (hard clipping) the LEDs won’t do anything. Vice versa, they will. In a guvnor, the LEDs only do a tiny bit as the opamp is clipping already. Etcetera. There is some science to it, but in the end, this is diy, so use sockets or alligator clips and just try to see what you like!

How Do I? Beginner's Paradise. / Re: PT2399 Not Adding Delay
« on: June 14, 2018, 04:28:21 AM »
Hmm, it seems the PT2399 chip is not working as it should as there is sound going in but not out. The chip is getting 5V on pin 1, but one thing to check is that pin 3 and 4 are connected to ground. Next, I would check your soldering on the IC socket and on the components directly attached to the IC. Since you already swapped the chip to no avail, it seems you can rule out a faulty IC (unless you got both from the same suspect supplier).

I am certainly no specialist on these delays, so perhaps somebody else can come up with a better strategy for debugging.

How Do I? Beginner's Paradise. / Re: PT2399 Not Adding Delay
« on: May 31, 2018, 09:14:49 AM »
Why have you been listening to pin 8 and 9? Don't know what should be heard there ... Perhaps listen at pin 12 and 14, but I would first listen at pin 3 and 2 of the mix pot (if there is delay there, that will narrow the problem area down considerably). Pin 6 to ground sets delay time, and depends on where you set the delay pot (2k7 to 52k7, so 41k looks fine).

Tech Help - Etcher's Paradise / Re: MADBOX mixer splitter problem
« on: May 29, 2018, 04:33:38 AM »
Are you talking about the TH Custom project? For bass, you might want to increase the value of the 220n caps; that may cure the loss of (low) frequencies, but that does not explain the clipping you experience. Are you using an active instrument? If it puts out quite a hefty signal voltage it might send the ICs into overdrive. With a passive instrument (or volume on the bass turned down) there should be no clipping, and if there is, there's something wrong (I would then start by checking whether the reference voltage VR is indeed 4.5V.

If the ICs are clipping due to a high input signal voltage, you could try a higher supply voltage. Make sure you check the max. allowed voltage on the filter caps C9 and C10 (which sees half the supply voltage) and make sure you stay well below their specified max. voltage! Alternatively, you could try rail-to-rail opamps that clip a bit later (but you won't gain that much headroom that way, I guess).

... by ordering the USPS to screw the UPU's rules would be right up their alley.
The rest of world seems to be ignoring those rules anyway. It’s only the US screwing their own small businesses as far as I can tell.

... I feel pretty bad for folks who just want to order a board or two and end up having to pay an equal price in shipping.
And ordering 4-5 boards is not going to help. Then you hit an import threshold and have to pay VAT, clearing costs, etc. which will double the entire price again.

VFE Projects / Re: Triumvirate - purpose of the series EQs
« on: February 03, 2018, 01:11:25 PM »
They second order filters, which are steeper than the more common first order ones. So that should give a better separation between the different bands.

Open Discussion / Re: Helping Hands Soldering?
« on: January 26, 2018, 09:21:14 AM »
Plus, populating the board is the fun part. I'd rather find a way to speed up the other stuff.
Hihi, good to see that I am not the only one  ;D. Soldering slowly and methodically works like meditation for me.

For those of you outside the US, what kind of shipping rates do you typically pay for PCBs when ordering inside of Europe, Australia, etc.?
It is usually weight based, and it is not always clear whether you pay for handling as well. For PBCs/small kits from TH Customs (Germany), I (Netherlands) pay 2-4 Euro (2.45-4.90 USD). FuzzDog (UK) is more expensive with postage; around 3.75-4.50 pounds (5.20-6.30 USD) for 3-5 PCBs and sometimes some small parts. Unfortunately, a large fraction of the nice-PCB-projects-for-DIY-guitarists is located in the US ... Time to move the order processing to Canada or Mexico  ;D.

This change aligns with the Universal Postal Union(UPU) Integrated Product Plan (IPP) which will require that format P (letters) and format G (flats) may contain only documents, not goods.
Interesting ... that in this respect the US is apparently at the forefront of adhering to international agreements. In Europe, I have not encountered this rule yet. I regularly order components (incl. 3pdt switches and jacks) from Germany, and up to a several hundred grammes they arrive in a letter for about 3 Euro. If that stops, this will become a very expensive hobby indeed ...

Very interesting, this is the first I've heard that this change was made by the UPU.
I find that hard to believe as this affects US to rest of the world only. The rest of the world can still send PCBs around, across national boundaries, at reasonable rates.

Global Annoucements / Re: 2018 Shipping prices start today
« on: January 22, 2018, 02:55:35 AM »
Well, that's the end of buying from the US for me, I'm afraid. Time to dust off the old etching skills ...

General Questions / Re: Soft true bypass?
« on: January 16, 2018, 10:40:15 AM »
There was an MB board (the Softie), about to be released, but withdrawn again. You can read about it here: Other suppliers are offering relay bypass boards though. I personally like the clunky, dead-simple, low-current requiring 3PDTs though  8).

How Do I? Beginner's Paradise. / Re: SMPS Project?
« on: January 16, 2018, 04:52:31 AM »
Tube Town in Germany has a kit for a module that turns 12V into max. 220V @15mA: I built one of these, and it works, but I still need to build a pre-amp with it, so it is not tested by me in practice yet (not sure if that would be a real recommendation anyway  ;D).

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