Testing and Listening to the Prescription Electronics Germaniums!
ฝัง
- เผยแพร่เมื่อ 29 ก.ย. 2024
- Let's do some testing on the selected transistors from the Prescription Electronics lot!
Then we'll throw the transistors in a tonebender and see what comes out :)
Buy a set of these transistors here (max 3 per order!): reverb.com/ite...
Follow me on instagram: @graybenchelec
Business contact: graybenchelec@gmail.com
I would like to compare results with the DIY GEO circuit which I use. It's a simple circuit with a divider for 9V. If the results are different whose off.
It took me years to figure out that “gain” knob on the Yardbox. Now I know it’s like adding a 2nd guitar vol pot so you can set it for roll off and not have to find it on your guitar.
Just ordered -- can't wait to build me a TB Mark III!
BTW, closed captioning likes your guitar playing:
[Music]
[Applause]
Thank you! Enjoy
Man I didn't even know he died, rip
Excellent. Tested, the MP-37 Ge Hfe 33 in circuit vs the mighty 2N2222a Si Hfe 430 transplanted into the same circuit. MP-37 is 1/3 the power of 2N2222a, however. I would consider the response of the Ge almost beautiful as compared to the non-movable rock hard 2N2222a. But I'm a tube guy so have at it.
The Aion Phobos pedal sounds much better than that, try some AC125
I would love to buy 3 sets plz to make some fuzzes for my friends plz. 😊
What's your Reverb Store?
Sets aren’t available yet, but there will be link in this video when they are!
Do you know who might be able to repair my Yardbox? It passes signal in bypass only. Thanks!
Shoot me an email at graybenchelec@gmail.com with some pics of the inside.
What is the ugly bug (chip) for in the PCB?
That is a voltage regulator, creates the -9V necessary for PNP fuzzes. Should be either TC1044 or LT1054
Sounds great, enjoyed the topic and demo.
Are MP16B transistors easy to come by (as far as germanium transistors go)?
A year or two ago I opened up my favorite dirt pedals and found they all had MP16Bs in them. I thought that was an interesting coincidence. Although, in the video, you said that Russian Germanium transistors tend to be lower gain, so, as someone who tends to turn their dirt knobs down, it would make sense that my favorite pedals have low gain transistors.
On an side note, I recently got a Rangemaster with an OC44 in it. As far as I know, this is the first germanium non-MP16B transistor I own.
You can still find them on ebay. What's changed over the past couple years is the way they're being sold. I remember seeing in 2018 or so, sealed boxes of MP16B, MP20B, GT403, etc. Now it's all loose transistors, which could be lots already picked through.
I really enjoy and look forward to each episode. I am new to the craft of building guitar effects. I do love FUZZ pedals and bought a set of these. Any directions on a pcb and parts list to build this pedal? Thank you!!!
Thank you! I know AionFX offers kits for their tonebenders every one and a while. Those kits do include transistors, but then at least you'll be able to mix and match. Otherwise any tonebender PCB will work, you'll still need to find your own resistors and caps, etc. Good luck!
It's getting really hard to find Germanium transistors with gain above 100 and decent leakage to build the other Tone Benders. The MkIII is very forgiving in that regard.
Yeah about 10 years ago i got a batch of Soviets and found one with a gain of 90. All others 50-70. but no leakage. I like them they don't have that squish. It308B
What’s the link to your reverb page? Thanks
I don't have the sets listed yet, but when I do I will post the link in the video description.
Sounds good! Are you selling some in the PI boxes?
Thanks! No plan for that at the moment.
😁😁😁😁
I would be keen to get a set please.
Sets are now available, check the link in the description.
GRAY BENCH, what is the minimum HFE value for a good sounding fuzz pedal? when a pcb board gets carbonized by burnt up transistors and FETS, does the transistors and FET have carbon material in their internal makeup? I'm not sure if 5mA for the collector current will give the same HFE and leakage values as a curve tracers because a curve tracers can supply a high test current so these HFE and leakage values can be wrong or false positives because of the 5mA collector test current?
It depends on the fuzz. I'm building a germanium Fuzzrite and the transistors only have an hFE of 30 or so. For a Fuzz face 80/120.
Generally I sort out below 40 hfe into a “low gain” pile. Hfe tends to rise with collector current, so while the tester should be accurate to its own parameters, you need to know those parameters to compare with other testers.
@@graybenchelec Does the biasing resistor values determine which HFE low gain or HFE high gain to use? or if the fuzz or overdrive pedal uses "diodes anti parallel arrangement" to use HFE low gain because of the anti parallel clipping diodes?
@@waynegram8907 Generally no, there are certain hfe's people like for certain circuits (80/120 for fuzz face for example), and the you'd vary the collector resistance to achieve a certain collector voltage. If you have anti-parallel clipping diodes you're probably setting up the preceding gain stage for minimal clipping, so hfe matters less.
@@graybenchelec The HFE value is based on what? the collectors resistance value or the preceding gain stage of the anti parallel clipping diodes?