The Amp Garage

I’m only running those at 350. That’s with a 5Y3 and the lower B+ option. I’m a bit hesitant, but some folks swear they’ve put them in a stock 5E3 with no longevity issues, which is much rougher than I’ll be treating them.

I've got an amp that I've recently finished building, and I think my last question is OT primaries. It's cathode biased and has multiple B+ settings. My plate voltage is between 350-400, depending on rectifier, PT secondary settings, and power tubes. The OT is a 3400 primary with 2,4,8,16 secondary ...

Well...as I try to figure out whether to submit another parts order or not, here are some pictures of it as it sits. Please note, I accidentally bent the LED leads to where they're almost touching, but I have bent them back apart. Some of the pics will reflect that. Anyone have a better option for h...

Thank you both for your replies. Since it was one in favor of swapping it out and one in favor of leaving it as-is, I decided to look up the data sheet (which, I admit, I should have done in the first place). According to the manufacturer, these are 450VDC working; 500VDC surge. Steve - your suggest...

My range is now (from memory) 2.6-4 Hz on slow, 3.9-9.6 Hz on fast. That's a very useful frequency range. Thanks! Yeah, I was playing over the weekend, and I don't see a need for any faster speed. I don't know how much lower it could practically go, but it's fine enough for me as-is. Glad I kept ti...

I would definitely experiment on scrap. It's a bummer that the ReRanch forum is down, but I understand why Bill is unable to think about it at the moment. I think that's probably the first forum I ever really frequented with any regularity. I'm going to mildly disagree with Phil about grain filling....

martin manning wrote: ↑Fri May 10, 2024 10:09 am

erwin_ve wrote: ↑Fri May 10, 2024 10:08 amStrange thing it happened to my mobile as well.

Same here.

Same. Glad to know it's not just me.

However, it seems reasonable to up that resistor to 680k or even 750k so the sum of the pot plus resistor is closer to the original. Good guess! I swapped the 220k with a 680k (which actually measures over 700k), and that was good. My range is now (from memory) 2.6-4 Hz on slow, 3.9-9.6 Hz on fast....

Parts arrived this weekend, so I made my (hopefully) final changes. Brief rundown: -Bias resistors were modified. Long story short, I was able to get the EL34s to 93.2% dissipation, and the 6K6GTs down to 101.2%. I think that's close enough for me. Anecdotally, people run 6K6 in a 5E3 Deluxe with no...

Just glad to see you back! Take care of yourself, and please don't hesitate to ask if you need something!

I hope so! I'm closing in on wrapping my Tremolux-inspired project. Waiting for more parts to come in...Hot Blue Plates (among others) on the Hoffman forums seems to think the paraphase is part of the mojo, from what I read (I read a LOT of 5E9-A threads while fleshing out my project). Here's a thre...

Maybe swap in a 5Y3 or 5R4 with the JJ 6V6? I was thinking about that also. Anyone else want to comment on that idea ? 5Y3 would probably lower the voltage, maybe 25V. 5R4 is a ruggedized 5U4, so no difference there. Respectfully, I believe the 5R4 has a higher voltage drop than the 5U4.

Maybe swap in a 5Y3 or 5R4 with the JJ 6V6?

Well, after a long time waiting, I finally got this together over the weekend. While everything *works*, it needs a few tweaks. Here goes: -Bias resistors will need modification. The 250/333/500 setup isn't quite going to cut it. With a 5Y3 and 6K6GT tubes, they're running at 108% dissipation with a...

Yeah, unless it's some kind of super-deluxe high-quality parts kit, that's way too much money. $800 CAD is around $580 USD, according to Google. I wouldn't pay nearly $600 for something that's known to eat tubes, whether they're boo-teek parts or not.