The Persuader

Build your own tube pre-amp pedal built around a JJ 12AX7 tube. Go from clean, warm tone to smooth, real tube overdrive.

This kit includes pre-drilled die-cast aluminum enclosure and all parts with easy-to-follow instructions. All you need to provide is solder and soldering iron.

The Persuader allows for easy access to the tube, giving you the ability to quickly experiment with different tube brands and 12AX7 tube relatives. A JJ 12AX7 is included with this kit.

Operates on a 9 volt battery or AC adapter, which is not included.

What people are saying about The Persuader:

"Great pedal and cool color! It makes a handy tube tester besides a real tube overdrive, you can get different gains and tones with an assortment of various tubes. Excellent and easy to follow instuctions with layout pictures, and you make it yourself!" "Very fun. Took me 5 hours to assemble, I've got almost no experience on the solder iron. It has got the good fuzz." "I really wanted a tube overdrive and this worked out great! It took me four hours, but it was well worth it, and the best part - is that I BUILT IT MYSELF!"

UPC: 609722124416

Sound Samples
Product Videos
Questions and Answers
Click each question to see its answers. Looking for general answers about Mod Kits? See our frequently asked questions.
Is this the same as the Persuader Deluxe without the tubes?
Answers (1)
MichaelT
Staff Member
March 6th, 2018
It is very similar, but the Persuader Deluxe also has an LED and a mini-toggle boost switch located at the top of the pedal.
Can I swap out the tube in this pedal?
Answers (1)
MichaelT
Staff Member
March 7th, 2018
Yes, we encourage it! Feel free to experiment with any common 12AX7 brands and alternatives.
Would this work for bass guitar?
Answers (2)
MichaelT
Staff Member
May 31st, 2018
Yes! We really like the sound of a bass with some tube distortion.
Verified Answer
Anonymous
June 8th, 2020
It works fine!!!
Hello. is it possible to purchase this kit in France or Europe? Thank you.
Answers (2)
MichaelT
Staff Member
October 8th, 2018
Amplified Parts ships worldwide. https://www.amplifiedparts.com/products/kits?filters=Brand%3DMod%20Kits
Verified Answer
Anonymous
June 19th, 2019
But thats still in US
I built the Persuader tube pedal, and it sounds great. I have an issue with the Gain pot. It is scratchy while adjusting. I've checked every connection, and I've tried two different, high quality pots, and they all have the same issue. It's not an issue while playing, it's just an annoyance while adjusting - fairly loud through the amp. Have you had this issue before? Any recommendations?
Answers (1)
MichaelT
Staff Member
November 29th, 2018
This has to do with the way the pot works with the BS170. A scratching sound is normal.
Verified Answer
What does the BS170 (and similarly the MPSA14 in the Persuader Deluxe) do? Is that being used as a voltage regulator?
Answers (1)
MichaelT
Staff Member
April 17th, 2019
These are being used to amplify the audio signal to drive the tube.
Verified Answer
Would this work as a preamp (for direct into a PA)
Answers (1)
MichaelT
Staff Member
May 13th, 2019
This really depends on what kind of signal the PA is expecting. This pedal outputs an unbalanced signal at roughly 5Vpp.
Verified Answer
Can it be used on a transistor amp?
Answers (1)
MichaelT
Staff Member
June 10th, 2019
The Persuader can be used in any signal path where an effect pedal would typically be found for both tube amps and solid state amps.
Verified Answer
can i use any tube that is not a 12ax7
Answers (1)
MichaelT
Staff Member
November 12th, 2019
You can use a 12AX7 or any other tube compatible with a 12AX7 such as 12AT7, 12AY7, 12AU7, 5751, and others.
Verified Answer
How much current does it draw? I'm adding it to a setup and need to make sure my power supply is sufficient.
Answers (1)
MichaelT
Staff Member
December 30th, 2019
The inrush current when first powering a cold tube can exceed 300mA. This spikes very briefly and settles to roughly 150mA using a standard 12AX7.
Verified Answer
Building the Persuader Deluxe: test points show no volts on MPSA 13 Trans at A or C. 'B' has the 7.3 VDC though. There is NO SOUND from the pedal. All solder joints good, multiple checks. Could the Transistor be faulty? overheated? Thank You!
Answers (1)
MichaelT
Staff Member
May 26th, 2020
It's a possibility. The transistor is somewhat easy to replace so it would might help rule things out. You might also want to double check that the 220 ohm and one of the 220K resistors didn't get swapped around.
Verified Answer
Along with a friend of mine who introduced me to your site we feel that the postage and Customs fees would be high for your kits purchased individually. You have however added a great deal of detail, work and effort to your site. In fact, enough for us to build a kit with UK sourced parts. We fully appreciate all of the effort you have made so would we each be able to donate something to you via PayPal in return? Kindest regards, Andy Riches
Answers (0)

No answers yet!

The description says its a preamp ? Does that mean I can plug a guitar with passive pickups into it and then plug the pedal into an amplifier expecting a line level input ??
Answers (1)
MichaelT
Staff Member
July 28th, 2020
This is a guitar pedal that offers the sounds of a tube preamp. The expected input is a guitar or guitar pedal and the output is a level similar to other overdrive, distortion, and boost guitar pedals.
Verified Answer
Built it, signal goes through but when turned on, signal is very low. I can use volume and gain pots (they both have some effect on the sound) but the overall signal is very low. Any recommendations on where to start troubleshooting?
Answers (3)
MichaelT
Staff Member
July 28th, 2020
We recommend working through the troubleshooting guide. It's on page 18 of the instructions here: https://www.modkitsdiy.com/sites/modkitsdiy.com/files/media_files/the_persuader_k-930_instructions_1.pdf
Verified Answer
Anonymous
August 30th, 2020
I'm having the same issues, and the link in the first answer is dead. Any help?
MichaelT
Staff Member
September 3rd, 2020
https://www.modelectronics.com/sites/modkitsdiy.com/files/media_files/the_persuader_k-930_instructions_1.pdf
Verified Answer
Following the troubleshooting guide (thank you!), I'm getting a reading at tube pin 1 of 8.8 (controls turned to min) and 8.3 (controls turned to max) WITHOUT the tube installed. With the tube installed, the respective values go to 6.6 and 6.2. Is this a problem with the tube, another pin, or something else?
Answers (1)
MichaelT
Staff Member
September 3rd, 2020
Make sure that your pedal is getting enough power. A power supply of 500mA or more should be plenty. Tube current draw can vary quite a bit so there can be some variation in the plate voltages of the tube.
Verified Answer
i have the same question as the other person. when the pedal is switched into bypass sound goes through clean but when its switched on very little sound comes through. i wen through the trouble shooting guide and all voltages seemed fine. i also checked the transistor and it is also fine.
Answers (1)
MichaelT
Staff Member
September 3rd, 2020
Using the AC signal tests or a scope can pinpoint where the signal is having issues. Also check that your power supply is rated high enough. 500mA or more should be sufficient.
Verified Answer
My pedal has worked for years but now it doesn’t. I have tested the tube and looked over the caps. I don’t see any bad solder joints in the pedal. Any suggestions on what causing the issues?
Answers (1)
MichaelT
Staff Member
August 4th, 2020
A cracked connection would be the likeliest candidate. These can be tough to spot though. Sometimes reflowing the solder on the entire build is the easiest way to rule them out.
Verified Answer
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