Blackstar HT1r amp or computer

[chunkitup]

Please tell me what is going on in this amp that it's this busy. I just wanted to change out a few signal caps to OD. Any help?

[nickb]

Extensive use of surface mount due to cost and availability is normal nowadays. There's no way you can reliably mount big heavy OD's in here. There's no point in any case as they use essentially the same thing (polypropylene film capacitors) in critical locations so you won't hear any difference. They are the rectangular grey caps on the PCB.

[loudthud]

Modifying something like this is not impossible, but unless you have the right tools, components, documentation, and experience, don't even attempt it. These days, the only place to gain the experience is to go to work at a factory someplace in Asia.

[Mick Bailey]

There are a lot of components in the signal path for tone shaping and a fair number of op-amps. Also you have a digital reverb IC. Just about as complex an amp gets considering it only has only two tubes. The mounting pads are small and close together, and mainly SMD. Take a look at the schematic and you'll realize the signal path is not so straightforward and consists of more than just a few caps. How you'd shoehorn and reliably mount ODs in there is a real challenge. There's also the possibility of the vastly larger caps coming into proximity of other components to form a coupling and consequential feedback loop. Either destabilizing the amp or altering the tone in a bad way.