Search found 1100 matches

by iknowjohnny
Wed Nov 16, 2016 6:25 pm
Forum: Technical Discussion
Topic: gain stage question
Replies: 31
Views: 5141

Re: gain stage question

The other which is more along the lines of what fender does is to used big bypass caps then tiny coupling caps like 500pf to lose the excess lows frequencies from the large bypass cap. Which Fender amp uses a tiny coupling cap for anything other than the input to the reverb circuit or the LTP PI? I...
by iknowjohnny
Wed Nov 16, 2016 3:49 pm
Forum: Technical Discussion
Topic: gain stage question
Replies: 31
Views: 5141

Re: gain stage question

By the way, why does this site get reported as a attack site when as far as i can see it;s not, and how can i get rid of that warning without turning it off for all sites in my browser?
by iknowjohnny
Wed Nov 16, 2016 3:47 pm
Forum: Technical Discussion
Topic: gain stage question
Replies: 31
Views: 5141

Re: gain stage question

I get how the coupling cap and cathode caps work, in fact thats why i changed them to this very different scenario. I always felt big cathode bypass caps made the amp totally unusable but that small coupling caps removed all that extra low end the big bypass cap allowed. It seemed to me like the sam...
by iknowjohnny
Wed Nov 16, 2016 2:46 pm
Forum: Technical Discussion
Topic: gain stage question
Replies: 31
Views: 5141

Re: gain stage question

that graph doesn't really tell me much as far as 100 vs 220k other than a bit more gain. Is that the only reason I see 220 so much more often in designs with large cathode/small coupling? Is more gain the only reason? Because it makes little sense looking at the graph. If all it does is add gain the...
by iknowjohnny
Wed Nov 16, 2016 6:12 am
Forum: Technical Discussion
Topic: gain stage question
Replies: 31
Views: 5141

gain stage question

I'm don't have much theory/understanding of the theoretical aspects of a 12Ax7 gain stage. But i HAVE noticed that there seem to be 2 opposite schools of thought on how to shape tone in cascaded preamps. In mine i usually go the marshall route with 100k plate, 820R to 1.5k cathode bypassed with .68u...
by iknowjohnny
Sat Nov 12, 2016 2:44 pm
Forum: Technical Discussion
Topic: Tone stack issue after loop install
Replies: 0
Views: 5318

Tone stack issue after loop install

Someone at another site gave me a design for a effects loop coming from the wiper of the treble pot for the send and the return into the master. This is a 2204 type amp tho 6v6 output. After the loop was in, and it works great by the way, i then noticed a issue with the tone stack. The treble pot no...
by iknowjohnny
Thu Jul 03, 2014 7:11 pm
Forum: Technical Discussion
Topic: Amp design and low end drive
Replies: 6
Views: 1064

Re: Amp design and low end drive

You didn't say, but whether you are trying to get this at home volumes, stage volumes, with preamp based OD or cranked amp OD are all things that must be addressed because those will change things radically. Note that petty and his band are big on vintage gear cranked up vs master volume tone and no...
by iknowjohnny
Fri Jun 27, 2014 1:33 pm
Forum: Technical Discussion
Topic: 4 stager
Replies: 49
Views: 4620

Re: 4 stager

You're making a generalization based on tweaking your specific amp, but that doesn't mean it's true for all high gain amps. Engls don't have any peakers and they are heavy as hell. Orange's Rockerverb is another example. Just sayin. True, but note that the amp in question has thru the years gone th...
by iknowjohnny
Sun Jun 22, 2014 12:13 am
Forum: Technical Discussion
Topic: 4 stager
Replies: 49
Views: 4620

Re: 4 stager

I've tweaked a cascaded preamp forever trying everything you can possibly imagine in every combination. One thing i came to realize is without peakers forget it. I'd find removing one or even all at times i thought sounded good. But in time i'd feel the amp isn't right and in a mix it's lost. No mat...
by iknowjohnny
Sat Jun 07, 2014 5:36 am
Forum: Technical Discussion
Topic: JJ's ECC803 reliability?
Replies: 17
Views: 3019

Re: JJ's ECC803 reliability?

It seemed a coincidence i saw this post just now. I just started using a 803 i had for a while now but never thought it sounded as good as the tung sol RI's i've been using for about a year. Before that i used the old 80's chinese i have a stash of. I liked both those tubes most of all the AX7's i'v...
by iknowjohnny
Fri Jun 06, 2014 1:37 pm
Forum: Technical Discussion
Topic: question regarding PT
Replies: 5
Views: 1042

Re: question regarding PT

Thats what the 150 is....a mag comp/classictone. The other is a hammond. I've used them both but haven't used the classictone for a long while and i was wondering is there was a difference i never really noted when i was using it. I thought maybe the 150Ma would make it less bright and hard as i tur...
by iknowjohnny
Thu Jun 05, 2014 9:38 pm
Forum: Technical Discussion
Topic: question regarding PT
Replies: 5
Views: 1042

question regarding PT

Say you have 2 PTs, both with the same specs but for one.....one of them is 250Ma and the other 150Ma. At low to medium volumes what would you expect to hear/feel thats different if anything with the lower current PT in a 2XEL34, 3X12AX7 SS rectified amp?
by iknowjohnny
Wed May 21, 2014 9:39 pm
Forum: Technical Discussion
Topic: 6l6GC vs 5881
Replies: 15
Views: 2116

Re: 6l6GC vs 5881

Don't wanna hijack, but can anyone describe what the difference in tone is with a 5881 over a 6L6?
by iknowjohnny
Fri May 02, 2014 6:25 pm
Forum: Technical Discussion
Topic: Lowering preamp voltages
Replies: 7
Views: 944

Re: Lowering preamp voltages

Ok, if thats the case tho, then i guess few or no amp's are designed with the idea that they might want a different voltage for different stages? I ask because i generally never see dropping R's of different values at various preamp nodes. yet it seems like that could be a good way to get what you w...
by iknowjohnny
Fri May 02, 2014 5:42 pm
Forum: Technical Discussion
Topic: Lowering preamp voltages
Replies: 7
Views: 944

Lowering preamp voltages

I know this is a stupid question, but then when it comes to electronic theory i'm pretty dang stupid so WTH.....Is it typical practice to lower preamp voltages by raising plate resistors rather than using larger dropping resistors at the PSU node? I always thought you would use the PSU resistors to ...