The Amp Garage

820R resistors may read as high as ca 1k. if you really crank an amp 15nf may differ noticably from 22nf, mostly from a quicker response with less blocking distortion To be honest, I do like the 820R mode—it adds a pleasant warmth compared to the 2.7K mode—but I’ve been a bit conflicted because, wh...

I also have a question I’d like to ask. The 680n cathode bypass capacitor for V2 was already in use previously. Currently, it’s wired to a switch alongside a 250uF capacitor; back then, it was mounted on the circuit board and connected to the switch. Typically, engaging a 680n capacitor should boost...

With the exception of #5, I’ve installed switches and tested for all the other points. 01.jpg 02.jpg Although some of these serve overlapping functions, each offers a slightly different nuance, which makes me want to keep them all. I could satisfy this desire by installing a few push-pull pots, but ...

I am currently deliberating on adding a few final switches and adjusting some component values—specifically regarding the SLP mode. There is no single "correct" answer here, so I am not looking for a definitive solution; rather, I’d like to hear your personal preferences. I have already begun some t...

A significant part of what I associate with the circa 1968 100w amps is the very relaxed filtering, especially by comparison to the amps from 1969 and later (I'm thinking specifically of amps with serial numbers with the prefix "SL/A"). While most 1968-dated 100w heads had 50uF reservoir values (sa...

I'm no switching expert, far from it, but I'm pretty sure at least some of those switches will pop or thump pretty good when switching them. I'm almost certain the NFB switch is going to have a decent thump. My best success with NFB switching is to start with the 'high resistance' value, then switc...

Thank you. Looking at the materials you shared, I realize that the component values ​​I had in mind for the SLP circuit were exactly those of the '68 model. Since I built it referencing the Mark Huss Plexi 6V6 and the 1959/1987x reissue schematics, it seems I effectively built it to '68 specificatio...

Hello. I have always considered the Marshall sound to be my absolute favorite, yet I realized that despite building various amplifiers over the years, I had never built a Super Lead Plexi. So, I decided to modify an existing 6V6 Blackface DIY amp to create a 6V6 Plexi. I incorporated 5F6A/JTM45 mode...

I ordered a custom shield panel to fit the location; while waiting for it to arrive, I used the string action gauge shown in the image above—securing it to the chassis with copper tape so that it acted as a shorting ground. This improved things significantly, but there was still some oscillation whe...

I ran a quick test. I looked around for a suitable object I had at home and spotted a string action gauge. Here is a photo of the area around the input/output jacks: 01.jpg As you can see, I don't need to cover it completely; simply blocking half of the output jack from the top makes the oscillation...

Thank you for the replies. I’ve successfully find the root cause. As you suggested, the issue stemmed from the input and output sections being too close to each other. Since the top control plate is detachable (as shown in the attached photo above), I connected it to the main chassis with clips and ...

Hello, I previously posted a thread about this. https://ampgarage.com/forum/viewtopic.php?f=6&t=38953 I built this amp now, but there's an issue and would like to ask for advice. It is an amplifier that allows switching between 5F6A, JTM45, and SLP modes. After make it, all mode switches function co...

Hiya i built a DC30 clone, and its bloody lovely. The FX loop is not super useable however. Ive put a dumbleator in it but it induces a fair amount of hum in the output which isnt a problem in the ODS I also built.. My thoughts are that the DC30 is a wonderful thing, and basically passive fx loops ...

you get less noise (resistive hiss) and thereby an improved signal/noise ratio. With the jtm circuit, the normal channel is usable. A forgotten trick is to adjust the volume of the unused channel. this affects the mixing of the channel and how the bright cap over the 270k mixing resistor affect bot...

It seems 100% of people are skeptical about 4-input. I am skeptical as well. However, since I have never properly used 4-input before, I felt that if I didn't try it in this project, I would remain curious forever, so I wanted to approach it in a similar way. But after hearing your opinions, it seem...