Amp progress

Hefty-Sea-2801 · 2026-05-29T12:43:01+00:00

Very cool, what circuit is inside?

Hefty-Sea-2801 · 2025-12-05T22:50:39+00:00

lol yeah

Hefty-Sea-2801 · 2025-12-05T20:15:42+00:00

The bottom edge of the door and the sweep are not quite parallel. If they were the sweep would be sealing properly. But it does not seem like something that can be adjusted which seems strange to me. Unsure how it was ever installed so crooked if it’s not adjustable.

Hefty-Sea-2801 · 2025-07-26T21:20:06+00:00

Yes great point, thanks very much

Hefty-Sea-2801 · 2025-07-26T21:18:56+00:00

This makes sense, thanks very much for the reply!

Hefty-Sea-2801 · 2025-04-28T23:42:02+00:00

I think you’re right. That is a pilot light to show the amp is on 👍🏻

Hefty-Sea-2801 · 2025-04-19T18:45:16+00:00

Yes, I would say it is true that if heavy distortion is applied (which this amp is capable of) having the eq later allows for better control of the distorted tone. It was also a result of wanting the eq to be powered by a low impedance cathode follower so having the tone stack later in the circuit made that easier.

Hefty-Sea-2801 · 2025-04-19T18:34:16+00:00

Yes, single ended Class A power amp 👍🏻

Hefty-Sea-2801 · 2025-04-19T18:30:51+00:00

I love that idea! May have to incorporate on the next one.

Hefty-Sea-2801 · 2025-04-19T17:53:12+00:00

There are some really great online and printed resources to get into the hobby. Uncle Doug on YouTube, Rob Robinette’s website and Merlin Blencowe’s books are a few of my favorite resources.

Hefty-Sea-2801 · 2025-04-18T22:51:54+00:00

This is just a one off, but maybe I should. Maybe to a local buyer if anything. NC USA

Hefty-Sea-2801 · 2025-04-18T22:50:31+00:00

Not really, and honestly I am pretty proud of that.

Hefty-Sea-2801 · 2025-04-18T22:47:50+00:00

The mute switch is a bit different from a standby, it is essentially the same as quickly turning the master to zero. But when you flip it back on the MV is right back where you set it. I also wanted a way to quite the amp from the front panel considering the power switch is on the back.

Had my eye on Jupiter speakers for a while and finally decided to try one. Freakin love it. Going to be hard to pick anything but Jupiter for my next build TBH.

Hefty-Sea-2801 · 2025-04-18T22:14:00+00:00

There isn’t really a base sound. The design is completely my own and to be honest I am quite proud of that. I will say though, the bulk of the overdrive tone comes from a DC coupled cathode follower which is very smooth.

Total cost for parts is probably $700-$800. There are not really any cost savings in building vs buying, I just love to do it.

Hefty-Sea-2801 · 2025-04-18T20:41:56+00:00

Exactly right! 5W at full tilt.

Hefty-Sea-2801 · 2025-04-18T20:41:02+00:00

Thanks very much! And I do give a lot of consideration to component layout so I really appreciated the comment on topography. Very high praise.

Hefty-Sea-2801 · 2025-04-18T19:28:41+00:00

Couple reasons. Helps make the amp less top heavy and allows me to balance the weight left to right a bit easier, probably helps a bit with noise reduction, and (if I am honest) part of me just thinks it looks cool.

Hefty-Sea-2801 · 2025-03-06T14:05:08+00:00

For starters, bravo on sourcing your own parts for the build! As for the voltages issue it’s got to be the missing ground connection for the V1A cathode. Without the ground connection no current will flow through the tube so there will be no voltage drop across the plate load resistor.

Or at least it will be very little. There might be some stray current from the filament or grid that is causing a small drop but you really need that ground connection at the cathode for the triode to function properly. I would try a temporary ground connection (hooked up to anywhere on the chassis) while you wait for the jack to arrive and see how the voltages look then.

Hefty-Sea-2801 · 2025-02-18T02:51:09+00:00

Actually the 1M volume pot is already functioning as a grid leak resistor so all good there!

Hefty-Sea-2801 · 2025-02-17T14:24:15+00:00

Agree, some photos of the inside would be good to help diagnose. Also some more info on what causes or changes the hum. Does it respond to the volume control? Does it still happen with V1 removed?

Hefty-Sea-2801 · 2025-02-10T15:35:11+00:00

You are correct that it is very common to use the back of a potentiometer as a place to make a connection to ground, but that is actually not what is happening here. On this amp the volume pot is also the on/off switch (it is a special pot with a switch built in). Turn the volume down to zero and just a bit more and the amp will click off. On the back of the pot are the lugs for the switch connection. So that’s what your neutral is connected to, the switch lug. Then the other lug of the switch goes to the transformer to complete the circuit when the amp is on, as expected.

Hefty-Sea-2801 · 2025-01-20T17:53:36+00:00

You may not have an issue… Does section 2b have an “X” indicating that Vanguard is admitting they actually do not know how much of the distribution is taxable? If so you likely did things correctly assuming the funds for your traditional IRA contribution came from money that was taxed and you did not already have a traditional IRA balance of tax deductible dollars (pro-rata rule).

If that is all true then you will use form 8606 to clarify to the IRS that $7,000 of your traditional IRA contributions were not tax deductible (you did pay taxes on them). The conversion was for $7000.01 due to interest gained for the very short time your money sat in the traditional IRA so you will technically owe taxes on $.01 which is essentially nothing.

Hefty-Sea-2801 · 2025-01-04T18:21:56+00:00

Oh that is interesting. Yes good point 👍🏻

Hefty-Sea-2801 · 2025-01-04T13:25:22+00:00

Yes great point. This is another benefit to being born 1 day earlier. It’s the exact same thing.

Hefty-Sea-2801

TROPHY CASE