Love it! Have done all the mods so far to mine and it sounds brilliant for what it is. Already have the Soviet tubes being pushed by grey glass RCA 6Sn7's but will to this resistor upgrade to keep everything safe and dbl check the value of those electrolytics for the base response. Can't freaking wait for the series to push pull this thing!!! Thank you for all you do and I'll be here waiting!!
mine doesn't have the headphone jack, and i have russian tubes in mine..... already did your cap/resistor mods from previous videos, and ordered a bunch of replacement tubes from Ukraine. ETA: i'm feeding it with a turn table (built in pre-amp) and feeding it from an Echo Dot's headphone jack. I put a scope on the output, cranked the amp volume, then upped the Dot's volume until i start to get clipping/distortion on the output and then back the input off. The output goes to a pair of klipsch R51Ms which help the little guy sound louder
Good suggestions! What is probably happening here is the cathode coating is evaporating off of the cathode and depositing on the control grid. This causes grid emission and your observed positive voltage on the grid. You might want to verify your filament voltage is not too high.
looking forward the mod that will increase its output -- actually I am looking forward and improvement mod on this amp. I love this amp and I already did your first mod with the rectifier cap and and driver tubes.
That's a rather compact amp. I'll hyperfocus on it later, I don't think I have 6P1s on my stash, but I do have 6AQ5s and 12AQ5s I could mess around with. Seems like a fun project.
I floated that idea on Audiokarma and looked for some advice on it's ability to drive a 10" Eminence 1058 speaker. Suffice to say, I was dealt with harshly and with unrestrained prejudice; spent 24 hours in the shower; jibbering and crying.
I'd made the previous mods, but still nothing special in improvement. After seeing this - yup, those resistors were fried! Sov tubes, new 330 caps and chassis resistors on the way. Thanks.
All done. Plus, enlarged existing chassis top holes and drilled some more. Would like to fit in a small Radio Shack transformer connected to incoming AC and bucked to 110 volts, but concerned about added internal heat. Using bucked trans externally now.
Hi i made a se kt66 with 6sl7 and i see on my oscilloscope that the clipping is on the negative part of the sinus ,i dont understand the phénomenon ,Thanks
Changing the cascode from a grid leak bias to a fixed bias, that stabilizes and reduces distortion. A grid leak bias cascode is better for use in a guitar amp.
Skunkie, I think you are doing a disservice to yourself by under estimating your knowledge and ability. On one of your recent video you spoke as though a push pull amplifier was out of your league. It's not. In 2015 was going to try and build a transistor amp when I came across tube information and switch. I have no experience in it, none. And decided to build a tube amp. While look at schematics, I realized that a 3 watt amp is not any different from a 20 watt, except in the parts. By just reading different books and articles, with no experience, and just a multimeter, I built the Mullard 5-20. That's why I know that with your knowledge you could build almost any push pull out there. I wanted to know if I were just lucky. So I built the leak 50 and then the mullard preamp. They all work great. I have no audio analyzer and no ocilloscope, but to my ear they sound great. ( I am timid when it comes to the oscilloscope). Take a look at the book Mullard Tube circuit for Audio Amplifier to how easy push pull is. It's going to be a breeze for you: trust me. keep up your positive vides.
I agree with you. I would start with a simple Williamson design and look for people's own takes on it. It's phenomenal design that allows for nearly limitless alterations and configurations. I have straight Williamson W5Ms. I have a Lafayette EL84 stereo push pull that is a modified Williamson that works extremely well. You can add fix bias if you want. It's one of the best designs I think to ever come out.
I have built a couple, what I mean is I don't intimately understand in depth everything that is going on. I want to get to that point before I start making videos and making various designs "my own".
Couple easy to do mods that makes a big difference, thanks for sharing.
Yes they do
Excelente trabajo, pulcro y compacto, me recuerda a las radios antiguas, pero con componentes modernos. Gracias por compartir!!
Love it! Have done all the mods so far to mine and it sounds brilliant for what it is. Already have the Soviet tubes being pushed by grey glass RCA 6Sn7's but will to this resistor upgrade to keep everything safe and dbl check the value of those electrolytics for the base response. Can't freaking wait for the series to push pull this thing!!! Thank you for all you do and I'll be here waiting!!
mine doesn't have the headphone jack, and i have russian tubes in mine.....
already did your cap/resistor mods from previous videos, and ordered a bunch of replacement tubes from Ukraine.
ETA: i'm feeding it with a turn table (built in pre-amp) and feeding it from an Echo Dot's headphone jack.
I put a scope on the output, cranked the amp volume, then upped the Dot's volume until i start to get clipping/distortion on the output and then back the input off.
The output goes to a pair of klipsch R51Ms which help the little guy sound louder
Good suggestions! What is probably happening here is the cathode coating is evaporating off of the cathode and depositing on the control grid. This causes grid emission and your observed positive voltage on the grid. You might want to verify your filament voltage is not too high.
100% it is too high used with 120V power, as the power transformer says right on it: 110V primary. I've been warning people about this for years.
looking forward the mod that will increase its output -- actually I am looking forward and improvement mod on this amp. I love this amp and I already did your first mod with the rectifier cap and and driver tubes.
That's a rather compact amp. I'll hyperfocus on it later, I don't think I have 6P1s on my stash, but I do have 6AQ5s and 12AQ5s I could mess around with. Seems like a fun project.
Very impressive 😳😳😳! You're a tube amp genius🧐!!!
Wow, thanks!
I agree.... impressive!!
It would make a good little bedroom guitar amp out of the box
I floated that idea on Audiokarma and looked for some advice on it's ability to drive a 10" Eminence 1058 speaker.
Suffice to say, I was dealt with harshly and with unrestrained prejudice; spent 24 hours in the shower; jibbering and crying.
I'd made the previous mods, but still nothing special in improvement. After seeing this - yup, those resistors were fried! Sov tubes, new 330 caps and chassis resistors on the way. Thanks.
All done. Plus, enlarged existing chassis top holes and drilled some more. Would like to fit in a small Radio Shack transformer connected to incoming AC and bucked to 110 volts, but concerned about added internal heat. Using bucked trans externally now.
Hi i made a se kt66 with 6sl7 and i see on my oscilloscope that the clipping is on the negative part of the sinus ,i dont understand the phénomenon ,Thanks
Made all fixes and mods, and running on 110 volts. Wondering if best paired with 4ohm or 8ohm drivers (small full range in a folded voigt)?
My guess would be 8ohms
Is this the 6P1 Parallel Connection ? with 6H8C pre amp?
Yes parallel SE.
That is one valve amp I never want to own.
What watts are the 2 mega ohm resistors?
1/2W is plenty, even 1/4W should be fine.
What exactly are the resistors that you added and moved doing?
Changing the cascode from a grid leak bias to a fixed bias, that stabilizes and reduces distortion. A grid leak bias cascode is better for use in a guitar amp.
@@SkunkieDesignsElectronics excellent. Thank you
Skunkie, I think you are doing a disservice to yourself by under estimating your knowledge and ability. On one of your recent video you
spoke as though a push pull amplifier was out of your league. It's not. In 2015 was going to try and build a transistor amp when I came across
tube information and switch. I have no experience in it, none. And decided to build a tube amp. While look at schematics, I realized that a
3 watt amp is not any different from a 20 watt, except in the parts. By just reading different books and articles, with no experience, and
just a multimeter, I built the Mullard 5-20. That's why I know that with your knowledge you could build almost any push pull out there.
I wanted to know if I were just lucky. So I built the leak 50 and then the mullard preamp. They all work great. I have no audio analyzer and
no ocilloscope, but to my ear they sound great. ( I am timid when it comes to the oscilloscope). Take a look at the book Mullard Tube
circuit for Audio Amplifier to how easy push pull is. It's going to be a breeze for you: trust me. keep up your positive vides.
I agree with you. I would start with a simple Williamson design and look for people's own takes on it. It's phenomenal design that allows for nearly limitless alterations and configurations. I have straight Williamson W5Ms. I have a Lafayette EL84 stereo push pull that is a modified Williamson that works extremely well. You can add fix bias if you want. It's one of the best designs I think to ever come out.
I have built a couple, what I mean is I don't intimately understand in depth everything that is going on. I want to get to that point before I start making videos and making various designs "my own".
I'm new too and I just picked up a hand healed 18$ scope from aliexpress and it has been so helpful when working on my class A transistor amp projects
China amps- cheap and flawed design(mostly)
And people email me saying I should sell my amps for the same prices as this China stuff...
@@SkunkieDesignsElectronics Only if you build in the same flaws and lack of QC😉