Search found 44 matches
- Tue Nov 18, 2014 5:40 am
- Forum: Technical Discussion
- Topic: Has anyone played around with lower Rp values on a 12AX7?
- Replies: 21
- Views: 3013
Re: Has anyone played around with lower Rp values on a 12AX7?
If you pull up the RCA tube manual then near the back you will find a chart that will cover all of your questions in full! Heck, then I guess we don't even need this forum. Well, I do use the tube manual frequently but I still really enjoy hearing other opinions when it comes to the sound of a circ...
- Sun Jul 13, 2014 4:59 pm
- Forum: Technical Discussion
- Topic: Checking a VVR install in DIY 5E3 build
- Replies: 12
- Views: 2216
Re: Checking a VVR install in DIY 5E3 build
Works great - the only difference being that it now has much more headroom esp. At bedroom volumes. There is tone and overdrive behavior change, but overall sounds good and gets the job done. Niki Hi Niki- Interesting that there is more headroom when you lower the voltages to the tubes of the whole...
- Fri May 02, 2014 1:41 pm
- Forum: Technical Discussion
- Topic: Switchable PS filter caps?
- Replies: 10
- Views: 1329
Re: Switchable PS filter caps?
I have an amp with a power supply similar to a typical 'wreck with parallel 47uF caps for the first node. With some guitars the amp is a little stiff and with some it is perfect. I had an idea to switch the ground of one of the caps so I could switch from 94 to 47 on the plates. I would probably pl...
- Sat Jul 13, 2013 12:10 am
- Forum: Technical Discussion
- Topic: I love repurposing old test equipment!
- Replies: 32
- Views: 4287
Re: I love repurposing old test equipment!
There's one on eBay now, but bid starts at $50 and shipping is close to $30. I just love the look of those. I want to use one for my three channel preamp project. They are cool looking but be aware that they are very small inside! The OD LXDXH is about 9X7X4 but the ID seems much smaller because of...
- Sun Apr 07, 2013 3:25 am
- Forum: Technical Discussion
- Topic: 1n4007 posts
- Replies: 12
- Views: 1987
Re: 1n4007 posts
Here is an example of reducing potential switching noise using caps.
http://www.valvewizard.co.uk/bridge.html
http://www.valvewizard.co.uk/bridge.html
- Thu Mar 21, 2013 4:56 pm
- Forum: Technical Discussion
- Topic: Octal Three Fat
- Replies: 3
- Views: 781
Re: Octal Three Fat
Thanks Phil. I'm going to put it into an existing chassis that's about 7x10". I'll use something similar to the first two stages then use the third stage for a cathodyne splitter into 2 6k6s. It too may be too tight & noisy but I'll let you know what happens.
Scott
Scott
- Thu Mar 21, 2013 1:05 am
- Forum: Technical Discussion
- Topic: Octal Three Fat
- Replies: 3
- Views: 781
Octal Three Fat
I found this schematic that I think I would like to try but can't find any coments about it here with a search. Has anyone heard this in action? Is this amp from the same Phil_S that I see here sometime?
Thanks.
http://home.comcast.net/~psymonds/Octal ... l3Fat.html
Thanks.
http://home.comcast.net/~psymonds/Octal ... l3Fat.html
- Wed Mar 20, 2013 9:40 pm
- Forum: Garage Talk
- Topic: Three Octal Fat
- Replies: 0
- Views: 1206
Three Octal Fat
I found this schematic that I would like to try but can't fine anything about it here with a search. Has anyone heard this in action? Is this the same Phil_S that I see here?
Thanks.
http://home.comcast.net/~psymonds/Octal ... l3Fat.html
Edit:( Moving) posting to correct forum
Thanks.
http://home.comcast.net/~psymonds/Octal ... l3Fat.html
Edit:( Moving) posting to correct forum
- Thu Sep 27, 2012 5:26 pm
- Forum: Technical Discussion
- Topic: Do Non-Inductive WW Resistors Matter In Git Amps?
- Replies: 6
- Views: 1391
Re: Do Non-Inductive WW Resistors Matter In Git Amps?
I'm thinking that non inductive resistors are good at high impedance places that don't have high voltages across them like the grids. (read that on one of the good sites around here, don't remember which one) Not sure about G2 though since they aren't so far from AC ground. I'll be watching for a go...
- Wed Sep 26, 2012 4:45 pm
- Forum: Technical Discussion
- Topic: 50's HP 711A power supply problem
- Replies: 4
- Views: 1260
Re: 50's HP 711A power supply problem
Interesting. I'm not up on that circuit but I would think it had something to do with a R/C time constant that works inverted but I don't see any huge caps. Must be the actual circuit that does it. I would like to know as well. Structo- I changed all the tubes, electrolytics and selenium rectifiers...
- Wed Sep 12, 2012 2:34 pm
- Forum: Technical Discussion
- Topic: 50's HP 711A power supply problem
- Replies: 4
- Views: 1260
Re: 50's HP 711A power supply problem
I will work on it this weekend & let you know what I find-Structo wrote:Interesting.
I'm not up on that circuit but I would think it had something to do with a R/C time constant that works inverted but I don't see any huge caps.
Must be the actual circuit that does it.
I would like to know as well.
- Mon Sep 10, 2012 8:43 pm
- Forum: Technical Discussion
- Topic: 50's HP 711A power supply problem
- Replies: 4
- Views: 1260
50's HP 711A power supply problem
Bought a 1954 variable power supply for breadboarding my amps. It slowly drops voltage over time. From 300 VDC to 280 v in 1hr. Other than tubes and electrolytic capacitors in general, any ideas on what part or block might cause this. Schem attached.
Thanks!
Thanks!
- Tue Jul 03, 2012 2:32 pm
- Forum: Technical Discussion
- Topic: VVR question
- Replies: 6
- Views: 1674
Re: VVR question
How does the whole amp scaled vs power amp only sound?surfsup wrote:I have a VVR now that scales the whole amp and am considering scaling only the power section at this point instead to see if I hear the difference.
Thanks
- Mon Jul 02, 2012 2:51 pm
- Forum: Garage Talk
- Topic: Black Korina Strat
- Replies: 16
- Views: 6044
Re: Black Korina Strat
Do you feel that is due more to the chamber or the wood?SeanA wrote:It is a nice sound, but not your "classic" strat tone.
- Mon Jul 02, 2012 2:34 pm
- Forum: Technical Discussion
- Topic: Gretsch 6159 Schem Question
- Replies: 5
- Views: 1501
Re: Gretsch 6159 Schem Question
As far as the reason for knocking the input triode signal down to ~1/20 ... look at the Supro s6424 it has the same input stage but the input stage goes directly to the phase inverter not into another triode. Thanks for the amp pointer. But, why build it up then knock it down that much? (It isn't a...