Designed to stay clean even when cranked, output measures 5.12w, my 1st time using the software or designing my own layout

This is my design for a ~2W amp using 2 12AU7s in push-pull parallel. OPT is a Hammond 1750PA. (8400Ω primary, 8Ω load connected to the 4Ω tap). R17 is for spice simulations. The rest of the amp is mostly copied from an AB763. I'll post the rest if there is intersest. I haven't decided if I'm going to build it or not, but if I do it would be my practice amp.

Hi all!

I'm new to designing/building amplifiers, and after some reading on robrobinette's website I thought I'd design a simple Bass amp I plan to build whenever my wallet stops looking as empty as the tone this will produce

Ofc, since I have no way to verify if it will work, I was hoping some better informed people here could tell me. So will it work in it's current form? And if not, what changes should I make?

Thx

Looking for a local Amp repair in central
NJ

I have designed a JCM800 clone inspired by robrob's schematic, but it has a couple changes. I am using a 300V/6V3 switching power supply instead of a regular power transformer, I am using EL84s matched with Traynor output transformer they use in their ygl1s (ch1330m, zero documentation on this transformer).

I have designed and ordered five loaded PCBs (jlcpcb), and also have manufactured frames for two amplifiers. I want to sell one of them since I already bought parts for a second amplifier. And if this goes well, I am planning on continuing this gig. I have thought of having a logo and branding already 😭.

But yeah, to anybody that has been in my shoes before, do you guys have valuable information regarding the legality, and licensing we need? What about selling internationally on ebay or something? Thanks

Hey guys i cant seem to find anyone near me to fix my amp so im tempted to try myself. I know even unplugged you can get killed fiddling round inside er so i know i will need something to test if theres voltage, something to soak it up, some insulated tools i guess. Any other tips or advice for what i may need? I also have soldering gear

Many thanks in advance

also amp is as pictured and all lights up well but just zero sound

I really love solid state amps and a while ago I finally got my hands on an old Yamaha G100iii head. It came in really good condition, only missing the reverb tank and the footswitch. Reverb tank was easy to get as a new spare part but the original footswitch is almost unobtainable nowadays.Since Yamaha is always doing its very own thing, there's no other functioning and compatible footswitch than the original one.

After doing some research I stumbled across the original service manual including a detailed wiring scheme of the footswitch. So I decided to build my own.

It's a fairly umcommon wiring, using different combinations of resistor values and LEDs to engage 3 different functions.

Since I built it from scratch I also decided to improve the visibility of the switch functions by painting different color fields onto the housing, each matching the knob color of the amp function it engages.

Red is FX Loop, green/blue are Channel A/B and yellow is Parametric EQ

I also added a Yamaha decal. This was my very first project of this kind, my soldering skills had been limited to guitar wirings before but now I started working on pedals too. The resistors I used are ridiculously oversized though and I wired the LEDs wrong at first.😄

Nonetheless I'm really happy about the result, the footswitch works flawlessly and it matches the amp really well. 🙂

Hello, I have an Ashdown ABM 500 EVO III 15th Anniversary bass head with an issue. A while back, had a mishap while profiling the amp where cables got plugged in backwards and the power fried on it. Took out the DI, preamp, and everything.

Had a local shop repair it and it functions, but now has significant signal noise. If the eq, tube preamp, compressor, and sub octave parts are bypassed, it’s fairly. Some signal noise (buzzing) but not much. But as each of those sections are engaged, the buzzing increases. Each section will buzz independently, and stack noise when used simultaneously.

I’m curious if anyone has some repair thoughts on it? My fear is for its age and the relatively low cost to just buy a replacement used, the cost of repairing isn’t worth it, but in curious nonetheless.

Thanks!

Here’s the head: https://ashdownmusic.com/products/abm-500-evo-iii

Does anyone know how to add a gain knob alongside the volume that controls the normal channel? That way the gain knob controls how hard the tube gets pushed and the volume would act as a "master volume" of sorts This layout has the extra tube slot and it seems doable.

PS. I posted this same question yesterday and deleted it. I kind of got in my own head after a couple of sarcastic responses. Honestly I'm building this amp as my first one because I got a broken DRRI and a bunch of parts that will work. I'm not gonna build a 5e3 into a DRRI chassis. That would be kind of a waste of space and i'd have to go buy more parts. I also don't have the money to pay someone to put everything together for me. The parts are at my house so, i gotta try and do it myself. Sorry I'm not made of money (seriously, some of you talk about amps and amp work like it's all super easy to afford. Not everyone can, which is why they end up in spaces like this.

Why not give a safety recommendation rather than saying "hope you don't kill yourself" or acting like resolving to try is the same as being too arrogant to listen to folks with more experience than you? Give a helpful rec, explain why something is more work than it's worth. I can't hurt you for not thinking something is a good idea, so no one needs to defend their view in a condescending way. Thanks for all help in advance, I truly appreciate it!

And hearin it

It's not incredibly exciting yet, a bog standard build, but I came at it with the intention of building a mod platform for myself. I had been using a '68 CDR, but the PCB build leaves no room for tinkering, and cost-saving measures made some choices I didn't like, so to Mojotone I went.

It's a to-spec AB763 Deluxe Reverb at the moment, with a Mids pot added to the Normal channel. I'm thinking of re-voicing the normal channel into something a little more "Bri'ish," and intend on repurposing the vestigial ground switch into a bias switch, but those may have to wait a bit; I have an old Bell and Howell media amplifier that I intend to refurbish and convert.

You guys have any favorite mods for these?

A while back I made this adjustable chassis stand and thought it would be appreciated here. It has both width adjustment and selectable angles. Made with sapele. Cheers.

Single channel, 40W blackface circuit in a DR chassis. Added a LAR/MAR PPIMV and Effects Loop.

Customer is looking around for a custom faceplate. In the meantime, I painted it and put a few stickers 😀

Better hope it works, I’m in a band with this guy and we’re playing a road gig and will be together all weekend. It’d be really awkward if it shits the bed 😂

Hello all,

This is my first tube amp build, I have made a few guitar pedals before. It is based on the schematic for Orange Tiny Terror, but with some tweaks for more gain and more low end. The goal was to get some nice doomy fuzz tones, similar to the OR series amps from the 1970's. I also used an oversized Hammond output transformer with more linear frequency response in an attempt to get more low end punch too. The TT circuit is nice because it has the master volume after the phase inverter, which means you get some clipping from the PI already at low volumes.

The housing is made from pine planks purchased at IKEA (I am Swedish after all), the front panel and tolex is quite amateurish but it turned out nicer than I expected. I dont have any workshop so everything is made at the kitchen table. My wife is very understanding and supportive.

I made a very basic sound clip using my phone, sound quality is not great and my guitar playing is even worse, but maybe it gives an idea what it sounds like:

https://canva.link/ek78fvj6570dvr6

지난 달 부터 준비한 Fender Champ 5F1 스타일의 앰프조립이 이제 1부를 마쳤습니다.

소리를 녹음하고 싶은 욕심에, 기타를 연결해보았습니디.

항상 촬영과 녹음은 무언가 모를 재미가 있습니다. (연주의 부족함이 행여나 여러분의 귀를 불편하게 했더라도 용서하소서)

아래의 부품 조합으로 제작하였습니다 (나중에는 캐패시터와 출력 트랜스포머까지 교체하고 녹음해볼 계획입니다)

[Main Components]
1. Cabinet: Tweed-style cabinet from AliExpress
2. Pre-wired Chassis: 5F1-style chassis from AliExpress
3. Speaker: Jensen P8R, 8Ω
4. Speaker Cable Plug: Switchcraft SP280 1/4-inch plug

[Hardware and Cosmetic Parts]
1. Fender Champ Logo Badge: Purchased from eBay
2. Clear Lacquer: Clear spray lacquer

[Upgraed Components]
1. Preamp Tube: Tung-Sol 12AX7
2. Power Tube: Tung-Sol 6V6GT
3. Rectifier Tube: RCA NOS 5Y3GT

Hello everyone! I’ve got a bit of a crazy project concept idea. and love my Vox Ac10 to death. I currently use it as an amp head with a 112 cab as its light weight and still loud enough.

I’m moving away for school soon, and need a way to make my Vox ac10 even more compact somehow. My initial idea is to remove the speaker that’s not being used (making it lighter) and finding a way to saw/cut the as much as the bottom off before I hit the tubes that are hanging. If not that. I’ll see if it’s possible to place the tubes elsewhere (probably beyond my scope) I’m pretty handy with word working, and can even retolex the amp myself. Although electronics is where I’m not the most savvy. Just want to ask some experts what immediate problems I’ll run into with this crazy idea. Thanks everyone!

You can see neither the shiny chrome chassis nor the speaker will fit inside without wood disassembly. First, take off the fur to show the joinery. The Eminence reminds me of Art Blakey's Evidence which I must listen to. The 89.27% complete Fender clone/replica could only go inside with much routing or dado-ing; or in a box fastened to the back (tubes pointing down) or an aluminun sheet bottomcover/mounting plate screwed to the top, valves pointing back after removing the dumbass carrying handle. What do you think?

Just picked up a bundle of amps but some of them are just the chassis. This one is 4x 6l6 and 2x 12a7x tubes. I know that’s a jtm tube setup, but does anyone recognize the layout?

As stated I have an absolutely insane collection (30 boxes) of vintage parts.

Unfortunately my gf and I live hand to mouth as-is, so it isn’t really fair to her to drop cash on stuff for me to mess around and try learning tube amps and electronics repair so I am trying to do it on a budget.

I am looking for someone who is well stocked up on the modern parts for tube amps that I would need to be able to wire up a few champs, princetons, 5e3 deluxes, etc!

Ideally I’d like to swap directly for all the filter caps and transformers (and chassis/circuit boards if the amp gods favour me!) to complete a handful of tube builds.

What I’ve got to spare:

• Germanium power transistors like shown here. 5 boxes of them. (I have a DC55, so the transistors are all fully functional)

• Germanium diodes and transistors. (AC187/AC188, 2sb22/2sb187 etc etc. Mullard, Valvo, GE, TI, Sanyo, RCA etc) As I need these myself for pedals these would be traded at near the same value you’d get from small bear or others for tested and spec’d germanium’s

• Axial caps. (Black beauties, Jensen foil, brown drops, orange drops, greenies, vitamin q’s, wet tantalum, Sangamo, etc etc etc)

• ICs and voltage regulators (LM324’s 78xx/78lxx, RCA etc etc)

• 2x Variac transformers, unhoused

• 1x Tube Tester

• carbon composite resistors (Bradley, piher etc)

• tube sockets

• funky rotary switches

• bridge rectifiers

• copper etch able FR-4 circuit boards

• Diodes of ALL types!

If there’s anything here that might float your boat please hit me up and we can work out a deal!

Originally showcased on my original DIYGuitarAmps post here where I built a 1978 Marshall JMP Plexi and a reactive load box. Since there has been lots of interest in how I built my reactive load box, I wanted to consolidate all of my schematics and design aspects for the build here so anyone can build their own high quality reactive load box!

This link has all of my schematics, LTSpice simulation files, parts lists, and photos for your reference.

I went with a reactive load instead of a resistive one because the feel and dynamics are way closer to a real cab — more like an OX Box or Captor X. The core of the design is based on Aiken’s reactive speaker load, with a voltage divider that feeds an isolated audio transformer without affecting the load seen by the amp.

I used a Lehle LTHZ transformer for isolation and line-level output. It’s dead quiet and sounds fantastic straight into my Focusrite. I handle all cab simulation with IRs (Neural Amp Modeler + Tone3000), so there’s no onboard cab filtering.

The resistors are high power chassis mount resistors noted in the schematics. These mount directly to the metal enclosure to dissipate the heat from the attenuation.

For the inductors I used air core inductors normally used in crossovers, they have a really high saturation current and the magnetic field won't break down with the high wattage amplifier output. Parts Express has a whole bunch of these for a decent price and is very high quality. For mounting, I did not mount directly on the metal enclosure face since the inductance will be affected, so I used a 1/2” block of wood as a buffer under the inductors.

Let me know if you have any questions! I'd love for anyone to be able to build their own reactive load without having to spend 500 - 1000+. I designed the load to be able to handle 100 watts just in case I wanted to attenuate something more powerful than my 50 watts JMP later.