Tube Amp Archive

ayan wrote: ↑Thu Aug 05, 2021 4:42 pm If it works fine as is... maybe you just want to leave it alone.

I'll leave it for the moment as is but, in case I need more volume I'll definately try the trick you mentioned. Thanks for sharing your experience Gil!

I'm sure the overdrive is very smooth, but didn't you lose too much volume that way? A trick that can be used is to up the 100K Ratio pot to 250K and fine tune the series resistor, if you'd like more volume available on tap. G. Yes I loose some volume but not that much. When I tried the 250k ratio ...

I added a 4n7 cap in series at the input of the OD section Added a 100k resistor at the output of the OD section, right before the ratio pot in the schematic Removed bright cap from the master volume Thanks! So am I correct in understanding that you have a combined 250K into the OD section, that is...

Thank you guys for your comments! I have to say that I couldn't have done this without your help and the extensive documentation available in TAG! One thing I forgot to mention were the final values that I finally selected for the OD section: the value of the resistor right before the level pot was...

Thank you guys for your comments! I have to say that I couldn't have done this without your help and the extensive documentation available in TAG! One thing I forgot to mention were the final values that I finally selected for the OD section: the value of the resistor right before the level pot was ...

Yesterday I took the amp to a friend of mine to test it. I made some changes to be able to test different OD configurations without having to open the cabinet. I temporarily replaced the presence pot by a 250K pot with one leg connected to the output of the OD and the other leg at the input of the l...

One other thing, which has been mentioned multiple times on this forum, is give the amp some time. Once you have a build that you feel gets pretty close to the # you are attempting, spend some time playing it and getting to know it. Very often I make a change and instantly regret it and want to rev...

Depending on what you want it to do, the 250K drive pot definitely can work but you will need to make some other changes (changes Mr Dumble made). Increase your reservoir caps to 330uf and reduce your bass pot size. Take a look at the 183 layout and you will see that he used the larger OD pots to a...

Have you tried limiting the amount of bass going into the OD section? Personally, I'm not a big fan of it, but you could try to add a 2n2 or 4n7 cap right before the 220k resistor leading to the OD entrance trimmer. This limits the amount of low end going into the OD, with a -3dB point of around 10...

My first impression was positive, although I remember Gil mentioned he was not in favour of using 250k pots in the overdrive section. I'm not sure what would be the drawbacks. One of the drawbacks being a 250k will add too much bass giving you the very problem you have? A fuzzy saw-toothed sounding...

One of the drawbacks being a 250k will add too much bass giving you the very problem you have? A fuzzy saw-toothed sounding low end :D Sounds like you want to decrease the low end content. In theory adding more bass should make things worse as you said, but not sure why, what I hear is bass seems l...

talbany wrote: ↑Wed Jul 21, 2021 9:18 pm BTW.Are those metal film's you have on the plates on V1 V2?

These are TKD 2w metal film. I use them on the cathodes as well.

Your scope results look pretty normal to me. I think what you're looking at is the effect of the cap and following resistor/pot on the low end. In square waves this is a way to see if you've got a bass boost or cut. When a square wave slopes like your yellow trace, you've got a bass cut. This is in...

And I'm interested to hear where you bought that 1meg J-taper pot! I can find them, but for unreasonable prices, or at Jelle with high shipping costs. https://www.electronicabaile.com/es/cts/cts-450gt-1m-a1m-logarithmic-potentiometer-solid-shaft-j-taper although prices were not too reasonable. 10,2...

I replaced the coupling cap by a new one and the result was exactly the same as before. I also unsoldered one leg of the 0.02 uF cap at the input of the PI and same result. Only when I disconnected the 100k ratio pot things changed. When I tested without the pot, the impedance to ground was 1M (the ...