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Vacuum Tube Audio Gear
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mlcasmey
Jul 18, 2023
In Questions & Answers
Just watched your brand new video on dropping in a pair of 5AR4 rectifier tubes in and biasing them. In your previous video you showed the wiring to the recifier tubes with the resistor and diode tag stripped in. Without removing these, won't dropping in a pair of 5AR4 tubes still yield nothing as the diode is still there? You still effectively have that solid state diode don't you? Can't want to get further into this project as I have one I'm about to open up and see how mine is built.
Thanks.
Mike.
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mlcasmey
Apr 18, 2023
In Show and Tell
This is my second R8 that has all of the part upgrades and Mod's except the GNFB Mod and the Volume Shielding. Did not need them. Great video series and great BOM. Thanks Stephe for the work you put into this project for us. Wonderful break from building guitar tube amps. And I learned about Audio Amps in the process. Just need to plug the hole from the headphone jack and repopulate it with the Tun Sol's up front and the Gold Lions in the back. Mike.
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mlcasmey
Mar 24, 2023
In Questions & Answers
OK. I just finished all of the parts replacement and wiring mods up through the front end. I have not done the bias boards. When I power up and all my front end tubes power up, The KT88 power up and are perfectly biased. But I only get sound on only one speaker. If I swap speaker leads the sound goes to the other speaker. So both speakers are good. But I can't get them both playing at the same time. Is there something in the parts upgrade work or wiring mods that would not give me power to both speakers. This is where I get stumped. Does any of this sound familiar to anyone? Mike.
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mlcasmey
Mar 21, 2023
In Questions & Answers
Having a great time doing the mods and looking ahead the the upcoming videos in the project. Got the R8 BOM parts sorted out. Just watched the video on tuning the GNFB and I see the R8 BOM has 2x 24K resistors and a recommended 330 Mica Cap. I'm not at my work bench right now, but where are these parts located in the amp? I assume they are on a PCB or several somewhere. It just was not shown in the video. Thanks. Mike.
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mlcasmey
Mar 13, 2023
In Questions & Answers
OK Stephe. I'm not quite an idiot, but before a break out my bundle of 18 gauge wire I use to build point to point guitar amps, I'd still like to get an OK on my understanding of tearing out the 120/240 block. Just to make me feel better, this is what I've figured out. Is this correct.
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mlcasmey
Mar 10, 2023
In Questions & Answers
What ended up being the ohm value of the original green wire wound resistor on the power supply board that was replaced by the small black one from Mouser? I know you said it was 2W but I did not catch the value. Also, does the 100uf 160 volt cap need to be audio grade. I could not find an audio grade one on Mouser so I bought just a regular nice Nichicon one, but unfortunately they are on back order. Should I be shopping somewhere else for an audio grade one? Thanks. Mike.
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mlcasmey
Mar 02, 2023
In Questions & Answers
The value of these caps is not mentioned in the video where the resistors are changed although she said one is an Audio Grade. From the published BOM I think it might be these two. Can anyone confirm which is which? Audio grade! 100uf 100V I assume this is the lower one and 100uf 160V I assume this is the upper one. Thanks. Need to get the dimensions on the two large caps. The ones she uses have no part numbers.....
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mlcasmey
Feb 22, 2023
In Questions & Answers
Just finished watching the A12 Mods videos. I'd love to do this one as it's simple and has few parts. However I'm used to building kits that come with the correct parts. I don't have to shop for them. There is a great list of the parts required, only 10 parts from Mouser, but when I hit their web site I'm completely overwhelmed with possibilities from different companies where a resistor for example that have the same description but several to pick from and range in price from 70 cents to 2 dollars, and I can't tell if a Cap is audio quality. Has anyone done this mod using the BOM provided that could give me Mouser part numbers for the 8 parts she uses? I'd love to know I'm getting great audio quality Resistors and Caps. Not sure what a 220R 10W wirewound Power Resistor is. Could not find that one at all. Would any of the audio experts out there give me a hand in getting the right part numbers for these? Greatly Appreciated. mlcasmey@hotmail.com Mike.
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mlcasmey
Feb 09, 2023
In Questions & Answers
Is there any difference in the RCA inputs in the back of the R8 that would affect the sound. They are marked pre-in, aux 2, aux, 1 and CD. What happens if I plug my lossless music player into one or the other of these 4? CD player into Aux 1...Does the amp care? Do they all go through the same electrical wiring to get to the pre-amp section? Thanks. Mike.
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mlcasmey
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