Revert back to original connection of PT primary. You created PFB which is a sure fire way of turning a good amplifier into an even better oscillator.eddie25 wrote:I I then switched the OT primary wires and hooked up the NFB again and the amp sounded even worse than before.
Search found 914 matches
- Sat Jul 18, 2015 7:11 pm
- Forum: Technical Discussion
- Topic: Weird issue with amp rejecting negative feedback.
- Replies: 10
- Views: 2001
Re: Weird issue with amp rejecting negative feedback.
- Mon Jun 22, 2015 9:31 pm
- Forum: Speakers and Cabinets
- Topic: Tubes and Safety regs
- Replies: 18
- Views: 4820
Re: Tubes and Safety regs
Guess what main ingredient of the electrolyte in the caps is. Yes, it's water. You heat it up it evaporates. Read up on app notes from serious manufacturers, they all advise to keep the caps away from heat sources, they warm up due to current passing through them. The data sheets also show how the c...
- Sun May 17, 2015 9:18 am
- Forum: Technical Discussion
- Topic: Help me to understand this please
- Replies: 16
- Views: 3137
Re: Help me to understand this please
There is a common confusion/misunderstanding of what anode (plate) load line represents. It is not a characteristic of how the anode (plate) behaves but how load ON the anode (plate) reacts i.e. it represents current drawn by the plate (anode) resistor from B+ supply as function of all B+ values ava...
- Fri May 01, 2015 8:29 am
- Forum: Technical Discussion
- Topic: What resistances is acceptable for ot transformer?
- Replies: 10
- Views: 1667
Re: What resistances is acceptable for ot transformer?
It's the number of turns not resistance that counts. I'd be concerned if inductance of primary sides differed significantly.
- Wed Apr 22, 2015 4:58 pm
- Forum: Technical Discussion
- Topic: Capacitor cocktail - types, locations
- Replies: 62
- Views: 12455
Re: Capacitor cocktail - types, locations
No liquorice, R.G.?
- Mon Apr 13, 2015 9:02 am
- Forum: Technical Discussion
- Topic: Noisy Power Transformer 120hz buzz
- Replies: 16
- Views: 2784
Re: Noisy Power Transformer 120hz buzz
Have tried to tighten the bolts holding the core together?
- Mon Mar 23, 2015 8:33 am
- Forum: Speakers and Cabinets
- Topic: Transmission Line Speaker Cabinets for HiFi
- Replies: 25
- Views: 7915
Re: Transmission Line Speaker Cabinets for HiFi
I've built a few pairs designed by Mr. Bailey published in Wireless World in 1972. I sold my own pair which I regret...
- Mon Mar 16, 2015 10:05 am
- Forum: Technical Discussion
- Topic: Cheap AC30 build with Antek Toriodal PT
- Replies: 36
- Views: 5974
Re: Cheap AC30 build with Antek Toriodal PT
So why not take the plunge and use a toroidal OT as well?
- Wed Mar 11, 2015 9:30 pm
- Forum: Technical Discussion
- Topic: There's a new Randall Smith in town
- Replies: 77
- Views: 13898
Re: There's a new Randall Smith in town
I built several variations of this amp, and I still have one with this MV, which is very similar to the Carlsboro and Mojave MVs: [img:1024:698]http://i514.photobucket.com/albums/t346/jaxmoons04/talon_schematic_1.png[/img] I have mixed feelings about how it sounds - sometimes I like it, but usually...
- Mon Mar 09, 2015 11:11 pm
- Forum: Technical Discussion
- Topic: There's a new Randall Smith in town
- Replies: 77
- Views: 13898
Re: There's a new Randall Smith in town
Variable cathode resistor in LTPI? Have a look at some old Gibson schematics.
A gain stage between sections of 2 gang pot? Peavey and others.
USPO should be on "Ridiculousness".
A gain stage between sections of 2 gang pot? Peavey and others.
USPO should be on "Ridiculousness".
- Fri Feb 06, 2015 8:48 pm
- Forum: Technical Discussion
- Topic: 4.3 kohms OTs
- Replies: 7
- Views: 1448
Re: 4.3 kohms OTs
2xEL34 on 400V for ca 45W output power or on 500V for ca 70W.
- Thu Jan 29, 2015 11:01 am
- Forum: Technical Discussion
- Topic: Output Driver Info
- Replies: 9
- Views: 1865
Re: Output Driver Info
The "driver" transformer is the phase inverter driven by the 6V6 SE stage. The PP output with 2xKT88 (originally this amp used GE 6550 ruggedized version made for Fender) operates in class B2 courtesy of the PI transformer supplying enough current to the control grids. This together with 700V on pla...
- Tue Dec 02, 2014 12:02 am
- Forum: Technical Discussion
- Topic: dc for the heaters
- Replies: 16
- Views: 3395
Re: dc for the heaters
Want hum free hi-gainer? Use separate transformer for preamp heaters. Well filtered DC and put the heaters on some 50-70V DC above ground.
- Mon Dec 01, 2014 11:57 pm
- Forum: Technical Discussion
- Topic: Spectrum Analyzer Test - 6PS vs 715P Capacitors
- Replies: 50
- Views: 7980
Re: Spectrum Analyzer Test - 6PS vs 715P Capacitors
Do I understand correctly that you changed ALL capacitors circled in your schematic between the tests? If so, this invalidates your conclusions as you have no way of knowing where in the circuit the most significant change occurred. Also, with 10% capacitance tolerance i.e. it can be 10% over or 10%...
- Sun Nov 30, 2014 12:37 am
- Forum: Technical Discussion
- Topic: JJ Punctured Cap Can (With dissection photos)
- Replies: 13
- Views: 2428
Re: JJ Punctured Cap Can (With dissection photos)
That goo is the electrolyte in gel form. It's what makes it work. At working temperature it liquifies. It will leak out. The electrolyte will spread all over amp's innards. The cap is junk. It's terminally ill. Read detailed data sheets, the part dealing with handling and application notes. It says ...