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Re: Balls Effects / Balls Amplification

201 by Dr Tony Balls
Kniferide wrote: Wed Aug 24, 2022 11:09 am
Dr Tony Balls wrote: Wed Aug 24, 2022 9:28 am
Kniferide wrote: Mon Aug 22, 2022 4:14 pm Now I want to build another one. I found the graphics mock up from the first one I built. Might build a 18vdc version and try fixed bias. It's a fun pedal.
How do you mean fixed bias? Also if you want any input about how I did mine just let me know.
I just mean a fixed resister value for the voltage to the Transistors. Mine had trim pots and was hard to dial in, gave an inconsistent result. Also, would a OpAmp like a TL072 be a viable replacement for the j201? Seems like you could get it on pretty small board. I'm going to dig mine up if I can find it and F around.
Ahh. The trimpots, once set, should be just fine but replacing them with a resistor works too. I just made a little breadboard rig to find the resistance I needed for biasing my three JFETs in this case.

Op-Amps are viable replacements, i'm sure, but i've always done this sort of thing with JFETs. Not for any particular reason it just works well and it's simple because its a direct 1-to-1 replacement for the tube triode and the only thing you need to tinker with is bias. There is a guy on the freestompboxes forum (call sign: BAJAMAN) that puts up his DIY designs, many of which are preamp ports from classic amps using OpAmps. The one below is for an SVT and if you compare it to the real thing you can see direct similarities and get a sense for how one might do that. I dont think it's gonna save you much board real-estate, though.
Image
Website: http://ballseffects.com/
Instagram: https://www.instagram.com/thetonyballs/

Re: Balls Effects / Balls Amplification

205 by Dr Tony Balls
VaticanShotglass wrote: Mon Sep 12, 2022 12:38 am Lovely Bassman preamp! I've got a small collection of various jfets I really need to sort and put to work. I gotta find my old notes about fixing up a little test jig to streamline it all. I also have very few germanium transistors I need to test and figure out what to do with.
For JFETs, depending on the usage, you really just want to bias them properly. You can make a little breadboard rig and figure out the right value resistor to use, OR just use a trimmer pot. Unless you're trying to do a FET-based Phaser...then you need to match your FETs for optimal results.

For germanium transistors, what i'd suggest would depend on gain readings and leakage. Certain things like a really leaky germanium, others dont. Rangemasters are still my favorite pedal thing hands down.
Website: http://ballseffects.com/
Instagram: https://www.instagram.com/thetonyballs/

Re: Balls Effects / Balls Amplification

206 by VaticanShotglass
Dr Tony Balls wrote: Mon Sep 12, 2022 9:59 am
VaticanShotglass wrote: Mon Sep 12, 2022 12:38 am Lovely Bassman preamp! I've got a small collection of various jfets I really need to sort and put to work. I gotta find my old notes about fixing up a little test jig to streamline it all. I also have very few germanium transistors I need to test and figure out what to do with.
For JFETs, depending on the usage, you really just want to bias them properly. You can make a little breadboard rig and figure out the right value resistor to use, OR just use a trimmer pot. Unless you're trying to do a FET-based Phaser...then you need to match your FETs for optimal results.

For germanium transistors, what i'd suggest would depend on gain readings and leakage. Certain things like a really leaky germanium, others dont. Rangemasters are still my favorite pedal thing hands down.
Thing about the jfets is that I'm not sure if they are in spec. I want to toy around with a Fairfield Barbershop style circuit and then later try to re-tune a pre-amp style circuit that just sounds too harsh to me as it is. I'm wondering if the jfets that came in kit might be trash. It has a few trim pots, but nothing on the range sound too good. I made some Runoff Groove circuits many years ago, the jfets just seemed to behave better.

I'm not really sure what the Ge transistors measure out to. I guess I need a little tester. Any recommendations?

I kinda want to take another stab at a percolator as I kinda miss the one I built years ago. For those purposes I could probably just cycle through the 5 or six PNPs I have in my box and just see what sounds best. But I don't know. Not really known territory for me. I still want to get around to doing a Selmer Buzz Tone sometime. I've seen videos of some others have made that sound good, like a lower gain fuzzy overdrive. I have the circuit from the Jext Telez model with adjustable voltage. All simple stuff except transistor selection. A few years back I Emailed Steve at Small Bear, and he said one of the FZ-1 sets he used to sell would work and they'd be back in stock in a week or two. Well, then Small Bear had a lot of other stuff going on, as you know. I've only thought about again recently.

Re: Balls Effects / Balls Amplification

207 by Dr Tony Balls
VaticanShotglass wrote: Mon Sep 12, 2022 2:05 pm
Dr Tony Balls wrote: Mon Sep 12, 2022 9:59 am
VaticanShotglass wrote: Mon Sep 12, 2022 12:38 am Lovely Bassman preamp! I've got a small collection of various jfets I really need to sort and put to work. I gotta find my old notes about fixing up a little test jig to streamline it all. I also have very few germanium transistors I need to test and figure out what to do with.
For JFETs, depending on the usage, you really just want to bias them properly. You can make a little breadboard rig and figure out the right value resistor to use, OR just use a trimmer pot. Unless you're trying to do a FET-based Phaser...then you need to match your FETs for optimal results.

For germanium transistors, what i'd suggest would depend on gain readings and leakage. Certain things like a really leaky germanium, others dont. Rangemasters are still my favorite pedal thing hands down.
Thing about the jfets is that I'm not sure if they are in spec. I want to toy around with a Fairfield Barbershop style circuit and then later try to re-tune a pre-amp style circuit that just sounds too harsh to me as it is. I'm wondering if the jfets that came in kit might be trash. It has a few trim pots, but nothing on the range sound too good. I made some Runoff Groove circuits many years ago, the jfets just seemed to behave better.

I'm not really sure what the Ge transistors measure out to. I guess I need a little tester. Any recommendations?

I kinda want to take another stab at a percolator as I kinda miss the one I built years ago. For those purposes I could probably just cycle through the 5 or six PNPs I have in my box and just see what sounds best. But I don't know. Not really known territory for me. I still want to get around to doing a Selmer Buzz Tone sometime. I've seen videos of some others have made that sound good, like a lower gain fuzzy overdrive. I have the circuit from the Jext Telez model with adjustable voltage. All simple stuff except transistor selection. A few years back I Emailed Steve at Small Bear, and he said one of the FZ-1 sets he used to sell would work and they'd be back in stock in a week or two. Well, then Small Bear had a lot of other stuff going on, as you know. I've only thought about again recently.
These things are fantastic but you're gonna drop probably $90 on one, so it may or may not be worth it depending on one's personal needs. If not you can always build a rig to measure leakage.
Image

Small bear has actually returned, just not run by Steve. Still a good source for certain things!
Website: http://ballseffects.com/
Instagram: https://www.instagram.com/thetonyballs/

Re: Balls Effects / Balls Amplification

209 by VaticanShotglass
Dr Tony Balls wrote: Tue Sep 13, 2022 9:08 am These things are fantastic but you're gonna drop probably $90 on one, so it may or may not be worth it depending on one's personal needs. If not you can always build a rig to measure leakage.
Image

Small bear has actually returned, just not run by Steve. Still a good source for certain things!
Oof. Yeah, not worth it for just messing around for kicks once every few years.

I am quite happy to see Small Bear back. The handover seems to be about as good as one could expect. For somethings they just have the best prices, and for others they are just about the only convenient source.

They even seem to have the Ge transistor kits up and going again, but only for FF and Tonebenders. I think the latter probably doesn't prefer the same set up as a Buzz Tone.

Several years back I used one of their sets to make a fun little modded Fuzz Face. I did a lot of stuff to it that I can't remember. The Fuzz dial is really and input level.
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Re: Balls Effects / Balls Amplification

210 by benadrian
Dr Tony Balls wrote: Mon Aug 15, 2022 1:50 pm HA. A blatant slap in the face to Ben Adrian's work.
Just saw this. I actually had a DT25 head that was a broken prototype that I was going to use for exactly this. Go crazy... I don't mind.

The DT series was just before my time anyway. The idea was sound (modeled preamps and a tube power amp with analog switching of topologies), but those amps were a bit unweildy and being the worst of both worlds to a lot of players. People wanting to spend $1,000+ on an amp either wanted all tube, or they wanted something more modeling-oriented with the benefits of a wide range of power settings and more built in models and effects.
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