MOD 102 Guitar Amp Kit

The MOD 102 is a great place to start for those interested in building their own tube amp. It is based on a classic American tube circuit design combined with a British style Class A output tube section. At low volume it produces a clean chimey tone that moves into smooth overdrive at higher volumes. All parts are included along with a pre-drilled steel chassis, wire and tubes (1 EL84 and 1 12AX7). Puts out at least 5 watts. The chassis layout is open for easy assembly using the clear, easy to follow instructions. You will need your own tools and solder.

MOD 102 Guitar Amp Kit Features:

  • All Tube Design (solid-state diodes used only for full-wave rectification)
  • 5W output power into 8 Ω
  • 1 channel
  • Vintage channel controls: bass, treble and volume
  • Vintage pilot lamp and screw-on jewel cover for power-on indication
  • Output Impedance: 8 Ω
  • Tubes included: one 12AX7 (preamp), one EL84 (JJ Electronic brand)
  • Hammond Mfg 269EX power transformer and P-T31 single ended output transformer.
  • Cathode biased class A power tube operation (no bias adjustment needed).
  • Point to point hand wiring using terminal strips
  • Carbon film resistors
  • Metalized polyester coupling caps
  • Pre-punched steel chassis
  • Assembled Kit Weight: 4.25 lbs.
  • Assembled Kit Dimensions: 10" Width x 6" Depth x 5 1/8" Height

MOD 102 Instructional Features:

  • Detailed, easy to follow instructions include high resolution computer drawings for parts list and every step of assembly
  • Tips for soldering and wiring
  • On-line technical support

Here is what people are saying about MOD 102 Guitar Amp Kit

"This was my first tube amp build and it was extremely easy and fun to do. I admit that I don't have enough experience with other amp kits to compare it to, but I cant imagine having a better starting point for tube amps, and the tone controls are a cool plus!" "Just the idea of this is awesome! Drive it with some P-90 dervish, dial to 10, strum chord, lean guitar against cabinet, walk across the room and have lunch while the noise self-perpetuates. Music to my ears!!!!" "Got the kit this week and finished it in about two days. Instructions and diagrams were excellent, would definitely recommend this kit for beginners. Fired up the amp for the first time and it worked perfectly. I am pretty impressed with the sound, has a nice tone and a lot more power than I would have expected."

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Questions and Answers
Click each question to see its answers. Looking for general answers about Mod Kits? See our frequently asked questions.
Can the power transformer be wired to work with voltages besides 120V?
Answers (1)
MichaelT
Staff Member
March 7th, 2018
No. This kit comes with the Hammond 269EX which is designed for 120V wall outlets only. Hammond does sell a 369EX version which has primary winding options to work with various wall voltages, but you would have to determine the wiring yourself. New mounting holes would also have to be drilled. We have provided a chassis hole modification drawing which offers a suggestion on how to accommodate the larger footprint of the 369EX.
Do I need a speaker to hook this up to?
Answers (3)
MichaelT
Staff Member
July 9th, 2018
Yes, you will need an 8 ohm speaker.
Verified Answer
Anonymous
November 10th, 2018
I have a spare 10”4 ohm speaker lying around would that work
MichaelT
Staff Member
November 12th, 2018
Using a 4 ohm speaker is not recommended since the output is 8 ohm.
Verified Answer
Could this be modified to use an EL34 in the power section instead of EL84?
Answers (1)
MichaelT
Staff Member
December 17th, 2018
It would require some significant modifications that would possibly include changing both transformers.
Verified Answer
Is this good for someone who doesn’t have any experience fixing or modding guitar amps?
Answers (1)
MichaelT
Staff Member
January 4th, 2019
This is a fairly easy build. You'll want to have some soldering skills as well as familiarity with components but otherwise no expertise is required. We offer troubleshooting advice as well. Be sure to check the tools list on pg. 3 of the instructions to make sure you have the required tools. If you need to brush up your skills I would recommend building the Piledriver first. It's a good first build since it has a good mix of components without getting too complicated and provides plenty of room to work. It's also a very useful pedal.
Verified Answer
Can a master volume be added in order to get distortion (high pre-amp gain) at low volume levels? If so, how?
Answers (1)
MichaelT
Staff Member
January 10th, 2019
We've never done a master volume mod but I would suggest looking into champ style amp master volume mods to get an idea of how it could be approached.
Verified Answer
Do you have wiring instructions for when using a 369EX power transformer?
Answers (1)
MichaelT
Staff Member
January 21st, 2019
Check pg. 1 here for a full list of all wiring configurations: https://www.modkitsdiy.com/sites/modkitsdiy.com/files/product_files/mod102-f_assembly_drawings_0.pdf
Verified Answer
Are the cold and hot legs on the bass, treble, and volume potentiometers interchangable as long as I stay consistent? I wired the backwards...
Answers (1)
MichaelT
Staff Member
February 15th, 2019
I would recommend rewiring them. The controls will be backwards if left reversed. It will also be easier to troubleshoot if there are any issues if they are oriented correctly.
Verified Answer
I've built this and love it. Is there a way to modify this so I can select the output ohm between 8 and 16? I realize a different transformer would be required plus some wiring changes. It would be ok if it was somewhat "hardwired" for one or the other, but I'm not intimidated with drilling holes for multiple output jacks.
Answers (1)
MichaelT
Staff Member
March 11th, 2019
It's definitely possible with a different transformer. We've never done it so we don't have any suggestions but Hammond usually has some great options for stuff like this.
Verified Answer
Can I use different preamp tubes to change the gain, like your preamp pedal?
Answers (1)
MichaelT
Staff Member
April 15th, 2019
Yes. We haven't experimented with it but the amp should be able to use any 12AX7 compatible tube such as the 12AU7, 12AT7, 12AY7, 5751, 7025 without causing any damage.
Verified Answer
How / where could ! add an Effects Loop ?
Answers (1)
MichaelT
Staff Member
June 21st, 2019
Effects loops are typically located between the preamp and the power amp. An effects loop usually is buffered using a dual triode or opamps. Adding either of these can be a lengthy mod. There are some premade effects loop circuit boards that can be power from the B+ which might be an easier approach. The easiest way would be to look into a passive effects loop but it might not have the best results.
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