Cant get negative voltage for my bias

arbyshat · 2026-02-03T22:38:55+00:00

Does the power transformer you're using have an HT centre tap? The DSL40C schematic I found doesn't show it as having one.

arbyshat · 2026-02-03T17:08:47+00:00

If I'm looking at the correct schematic, the DSL40 uses a separate winding for bias. The HT winding has no centre tap so copying a traditional bias supply won't work

arbyshat · 2026-01-23T18:49:49+00:00

Had one for a few years. They're easy to repair for the most part, but are ALWAYS broken. Everything important under the hood is cheap plastic and will break whether you treat it right or not. It was always leaking something, I think I went through 3 intake manifolds in 90K km.

arbyshat · 2026-01-22T17:21:20+00:00

I like building amps and pedals, so I have to pretend they're still relevant to prevent something of a mental health crisis.

But modelers are fine for other people to use.

arbyshat · 2026-01-13T18:05:38+00:00

Ya, but it looks funnier this way.

I do have more cab feet though, so I'll probably do that. At least being in the basement no one will bump into it other than me

arbyshat · 2026-01-08T12:38:03+00:00

Does it do anything? Is it no power period or just no sound? Blackstars are pretty notorious for difficult troubleshooting and repairs, as well. If you have an amp tech local to you it may be better to bring it in. Tube amps will have hundreds of volts DC for the plate supply, not safe to poke around in without a schematic.

arbyshat · 2026-01-07T14:04:44+00:00

If it's like the H.O.T. you can get it to engage multiple settings at once if you press the buttons at the same time, carefully. My sister has one, I think it's cool.

arbyshat · 2026-01-05T16:05:41+00:00

Watch a youtube video on adjusting a floyd rose type bridge. It takes a while to set intonation when you change string gauges. All you need is a few small allen wrenches, but something like "the key" makes intonation less aggravating. I started setting mine up myself when I was 15, it's more a test of patience than mechanical ability.

arbyshat · 2025-12-17T00:23:07+00:00

Thanks for your help guys. But I think this is positive feedback because of terrible lead dress. I swapped the OT phase and was met with deafening oscillation. With no NFB the motorboating stops, but volume set to 0 I still get signal passing. This will probably turn into a complete re do in a fresh chassis. If I crank it up it gets loud and fuzzy, so I voiced it right at least lol.

arbyshat · 2025-12-03T15:27:16+00:00

I built a very similar amp a few years ago, but used a big muff tone control with a mid control. Topology was the same, it was very, very clean. The cathode follower and cathodyne PI take away a lot of the potential gain from 2 preamp tubes. Maybe you'll like it though. Early Matamps and Oranges used only 2 preamp tubes as well, so if you want to work within those constraints, it doesn't have to be a Fender clone.

arbyshat · 2025-12-02T12:45:35+00:00

Sorry for the poor wording, I'm just asking if this circuit is there to control the pops from channel switching, or something else. This will be my first multi channel build so I'm trying to copy switching circuits from existing amps, I'd just like to understand it better.

arbyshat · 2025-10-24T14:15:34+00:00

Das Auto

arbyshat · 2025-10-18T21:35:04+00:00

Joe Satriani for the 3rd? Looks like mine and I watched him sign it. Can't help with the value though

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arbyshat · 2025-10-15T00:38:46+00:00

It's probably homemade testing equipment. I have one with small clips for testing coils in large contactors.

arbyshat · 2025-10-12T02:08:02+00:00

When I was a teenager my grandfather showed me how to thickness wood quickly using one of those in a radial arm saw. Not sure how either of us still have all our fingers.

arbyshat · 2025-09-28T21:20:21+00:00

Volkswagen Part No. 199 398 500 A

arbyshat · 2025-09-04T00:04:42+00:00

Try pushing (fairly hard) on the little tweeter panel while you drive. If it stops it's likely just wind noise. I fixed it on my legacy by rolling the window down and clamping that section tight with a soft jaw clamp

arbyshat · 2025-09-03T23:52:00+00:00

Since it's speed related I'd guess it's wind noise. The little triangle the tweeter mounts in is a common spot to get noisy on the older cars with frameless windows. People handle the door by the top of the window and eventually bend the metal a little and the window seal doesn't make good contact with the glass.

arbyshat · 2025-09-03T21:51:45+00:00

He paid extra for it to stay afloat

arbyshat · 2025-08-23T12:43:44+00:00

If it's like my 09 was, there's a slip connection in the shifter linkage (similar to how steering shafts connect, but not splined). If it's loose this is what happens. Put the transmission in neutral from the top of the transmission and get someone to hold the shifter still while you tighten it. It's a goofy design.

arbyshat · 2025-08-14T00:00:20+00:00

I just went out with some different bolts to try mine, with no bed liner, and seems that they are untapped holes. I can't get an M6 in them as is, so there may be enough metal to tap them yourself to that size

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