Favorite Threads and Posts in "Tubes" Forum

[Tony]

Posted new P-P power amp design

6C33C-B. PP or SE ?

6L6GC AB2 Amp

Building a Aikido preamplifier

[dopkomachine]

Here is a good selection of schematics:

http://www.tubebuilder.com

[djk]

Server not found

Firefox can't find the server at www.tubebuilder.com.

[alecu7]

Originally Posted by djk

Server not found

Firefox can't find the server at www.tubebuilder.com.

Same here.

[M Gregg]

This seems to work well,

Loose Tube Bases

I used clear nail varnish worked quite well on 6L6G Brimar.
Thank's Ty_Bower.

Regards
M. Gregg

[igaar]

Finger nail polish! I use that to fix tears and glue down old spiders back to the magnets as well in speakers that have seen better days, any color will work by the way. Something else that could be good for tube bases is "slow drying super glue" it can be bought at the hardware store like Ace or one of the other chains.

[radio]

Hello!
The measurements refer to the preamplifier is given below in Scheme (Figure 1)!
Please someone let that little comment about this preamplifier, if it does as a power preamplifieramplifier.
Feedback to be about the sound and display measurements if it worked.
If someone izradijo this pretpoačalo and made some measurements and some show here (frequency response and attitude towards the second and third harmonic!!?)
Many thanks in advance!

[kevinkr]

Zigzagflux's thread on FFT measurements performed on his system: D/A preamp FFT measurements for review plz for persistence and methodology. Quality of all responses is also excellent.

[richwalters]

SOme wondered how that that BiG 200+200W parallel p-p project is going; pic of the business end. It may look horrendous but it's in order. In all about 9 months work in evenings the 100KHz SMPS taking up alot of development time. Some wiring needs tidying up but in the most part the 750W SMPS (within square can) with dual voltage boost power supply runs as expected as do the supplementary power boards; all with hot logic switching and watchdog detection, with programmable stage USB interface.
This is systems engineering complexity, so this project isn't for first timers nor beginners as considerable RF experience is required. The power amp circuit is remarkably basic; capable of bridge mode operation but it's the safety aspect of the very low impedance power supply draws attention to protection. Many don't like SMPS in power amps supplies; the advantage of excellent regulation is a real plus for dynamics.
Some features:-
AC soft start; duff cable and brownout jerk hiccup; 360V intermediate driver stabilised B+; logic controlled auto switching B- with hi & lo power with programmed B+ droop for MI; auto cathode current monitoring (important in bridgemode); large tolerance AC operation; wideband input transformers; DC front end heater; watchdog bias and overvoltage failure protection. Channel separation guaranteed -70dB at 15KHz; hi power thd 0.1% at 200W & lo power 0.05% at 35W.
This amp represents a considerable investment in old and new concepts.

Next to come; in a few weeks time, the complete power running spec with photo.

richy

[SY]

I am sincerely impressed!