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It's still a bit of a rats nest but it sounds good Not quite finished there but was getting close

Do you think it could be the noise floor of the scope becuase when i switch the probe and scope to 1x it drops to 10mv and if i switch back to 10x on the probe and scope it goes up to 20mv the grid resistors are all soldered directly to the socket nice and close the wires are a bit of a mess...

I actually have some of them SO-239 around i could put it on there lol see if I can talk with the truckers lol but thats a bit higher 27mhz I've been checking every thing and it is coming in on the input of the amp seems like its in all of my sources

I seem to be getting some high frequencies in my amp around 4mhz-25mhz around 20mv peak on the output I don't think I would call it an oscillation but my question is if i add capacitor to the input or maybe a higher resistor would it help to remove that or should i just not worry about that thanks

I was thinking it was only 0.5 db down at 8k it really dropped hard at 15k I did add 1k grid stoppers to all the 6bq5s and I did add the efb circuit I do have other caps I may play with but I'm pretty happy with it there

With in 3db 20 to 20k looks good enough for me and i cant hear past 15k anyhow

I think I would have to make a voltage divider and connect it to the center tap for it to work with my transformer

I didn't realize it did that but it does make sense now that you say that I understand why it's there Now does it matter where I put it in the string can I add it to the end or should I have it hooked up before the first tube heater I don't really think it should matter but I've been wrong so...

I'm going to try with out it first I think I can always add it in later I'm getting my first oscilloscope Monday with fft if all goes as expected I might check to see what it does with and with out it Thanks again

I've got one more question why on the efb schematic do you hook the output of the lm337t to the 6.3v heaters I suspect is has to do with removing 60hz hum I dont really have an issue with hum at all and my power transformer has a 6.3v center tap if I'm correct I would not need to hook the efb...

thanks i was kinda thinking the same but I wasn't sure I need to work on my math skills

Ive got one more question on the 5k pot on the efb schematic how many watts does it need to be I was thinking about getting a 2 watt pot but if i could use a normal 1/2 watt pot i would already have it

that load line simulation tool looks really great and I'm going to play with it a lot I'm sure. I have LTspice I just have not got it figured out yet lol I'm good with a soldering iron and have basic electronic knowledge but have no idea how to make LTspice work. It seems as if my best...

looks simple enough it also looks like if i was to use 4 5k pots instead of 2 2k pots i could bias every tube separably I just dont know if its going to be worth it. I think i read some where that you have used the efb bias Gadget73 was it a big improvement or would you just continue to use a...

lets say i want to add efb to this amp with the lm337t and I wanted to bias left and right channels separately could I use 2 LM337t one per channel and still use a schismatic like his or would i need to double the resistance from like 330k to 660k. Any help would be greatly appreciated...

Ive removed the screen resistors I have about 310 volts on the screens now Ive added a bit more feedback I went from 6.8k to 5.4k ohm and the bass may have tightened up a little bit This little amp does sound really great I don't have a real good way to measure frequency response but the half...

Ya I could give it a try I will have to get one for c5 I could remove the resistor on the screen or switch them to 100 ohm the voltage wont be to much higher

them 12at7 are getting pretty warm set there but here goes round 2

thats what the problem is my source keeps dropping or my volt meter can read above 8khz properly

A set i pulled off an old rca console it has 8 ohm and 4 ohm taps kinda like another that i got working and sold a few years ago but that one only had one set of 4 ohm taps i think i would have thought hf would come out easy and lows would be hard but maybe I'm at the limit of the out put...

yes it is 100pf sorry but i just took it out completely and it test about the same what am i missing

I ooppsed it I was using a new program and I was changing the frequency for a channel that i had muted so all test were done earlier with one frequency this is what the graph should have looked like I did change that resistor so i think it comes down to poor feedback I didn't think that could...

I hooked up a bit of a poor mans scope to my other phones mic Jack and 2 200k resistors and ran a 1k square wave for what ever its it's worth lol it dont look all that square but it could be how I was generating it or recording it 500hz 100hz I'm just curious what is causing the slope what do...

ok so i messed up the frequency response is still pretty bad or about the same this is with a 1k ohm resistor on r1