• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

The Red Light District - another PP EL84 amp

CharleyW said:
Is there any way to accomodate multiple sizes of caps rather than just one person's fave?

Yes -- within reason -- you just place a soldered-through "hole" on the trace in question and attach it to the net. The WIMA FKP1 pins are a smidgen bigger than the Roederstein MKP's. The pins are spaced about 550 mils (14mm) wider A boutique capacitor will have a much larger LWD -- since telekinesis isn't working at the moment you might wanna tell me exactly what you are looking for.
 
jackinnj said:
since telekinesis isn't working at the moment you might wanna tell me exactly what you are looking for.

Apparently the google isn't, either.

Lengths of various 100nF capacitors (in inches) (Your board seems to spec 10n, but SY's schematic says 100n -- 10n is probably a little small):

AudioCap PCU 1"
AudioCap Theta 1"
AuriCap 0.8"
Cardas 1.1"
Dynamicap 1.15"
Jensen PIO (Al and Cu) 1.4"
Jupiter 1.1"
Kimber Cap 1.1"
Hovland 1.75"
Multicap RTX 1.5"
Mundorf Silver/Oil 1.42"
Mundorf Silver/Gold 1.42"
Sonicap Gen 1 0.77"
Sonicap Gen 2 1"
Sonicap Platinum 1.2"
V-Cap TFTF 1.4"
 
Fired!

Jan, 30th. 2am. Fired up the RDL. Nice, but... my sons are sleeping. Wife also. Only Solveig song by Grieg or similar. Ok, let's play some Chesky's tests tracks. I can smell some isolation melting. Smelling. No signs of melting. Going to have another CD. Isolation melting again. Nooo! My wife bought hiace and now blooming! A man with a stick and can does not stop where claims he does. Gosh. Right channel is louder! Why?! Swapping tubes. Nope. The same result. Darn. Time to sleep. 7am. My youngest son is up. Iron is wrong? Output tubes are not matched? Need to re-check voltages. Hmm. Quite ok. Except for 6P14P-EV current. Too low, only 56 mA. Time for breakfast. Eaten. Another coffee. I must have done something wrong. Hmm. 6P14P anode voltage check. A bit of a difference. But, hey, why? Heater voltage? Check. Daaaamn! Wire fault One OP tube is supplied with double heater voltage! One LED array is gone, only a couple LEDs survived after me not quite carefully attaching leads. Sparks. Ooops. 20 mins to recover the array. Heater wires corrected. LEDs recovered. Time to check again. Good. Better.

Now some music. Anna Netrebko. Sweeet. Bela Fleck. So much bass. Fast. Madredeus. Lovely! WAF* increasing. Mariza. Great! Marcus Miller at the concert. Sons dancing! Some J.S.Bach. Splendid! God ... you, SY! My wife loves me (or my amp) more and more.

PS. And now Polish handball players playing against Craotia. I hope they are as good as the amp.
 
As far as George's PCB's, it's my understanding that the board he ordered produced is his Simple P-P design and the one he is currently developing is a large more robust universal P-P driver board.


I have been know to be wrong, but I think this is correct.
 
As far as George's PCB's, it's my understanding that the board he ordered produced is his Simple P-P design and the one he is currently developing is a large more robust universal P-P driver board.

Yes, I have placed the production order for the Simple P-P board. It was delayed about a week because I sent the wrong credit card number. 😱

It doesn't take a rocket scientist to figure out that the Simple P-P, the RLD and the Bevois Valley amplifiers are all very similar. Some could say that we are all good copy cats. The reality is that this is a very good design, and I tried several designs (most people know that I prefer the LTP) before I settled on this one. It truly is the best "simple" design out there. There are better designs out there, but they are far from Simple. In this case there are definite implementation differences.

The Simple P-P follows the Simple SE approach. All of the amplifier circuitry including the power supply and output tubes are mounted on the PC board. Connections to the PC board are made using the same screw type connectors used on the Simple SE. The reason for this is simple. It is what people have asked me for.

Is there room for two different boards? I hope so, I have 100 Simple P-P's on order. The Simple SE and Simple P-P are targeted at the user that wants an easy to build, yet good performing amplifier. The Simple SE sold well enough so that Tubelab might have shown a profit last year if the ecomomy hadn't collapsed. Two customers ordered 10 boards each during the last year. There is some serious amplifier building out there.

I think that the driver PC board discussed here requires some thought and experience to use. I might even buy one, although I never finished those Aikido boards that I bought.
 
OPT replacement

My old ZATRA OPTs seems not to be quite symmetrical - I suspect one is like shorted because the volume in one channel is lower than in the other. What is your favourite, yet within a low budget, OPTs for EL84 PP?

Pawel

PS. I am beginning to be a LEDs bias fan - I soldered 2 (ch) x 4 x 26 LEDs = 208 pcs for my friends ECC82 + 6C4C (6s4s) SE parafeed amp. Huge difference compared to RC bias. New amp.

PS2. In Warsaw, PL RLD is called "Pigalak". From French Pigalle.
 
Re: OPT replacement

yagoolar said:
My old ZATRA OPTs seems not to be quite symmetrical - I suspect one is like shorted because the volume in one channel is lower than in the other. What is your favourite, yet within a low budget, OPTs for EL84 PP?

Pawel

PS. I am beginning to be a LEDs bias fan - I soldered 2 (ch) x 4 x 26 LEDs = 208 pcs for my friends ECC82 + 6C4C (6s4s) SE parafeed amp. Huge difference compared to RC bias. New amp.

PS2. In Warsaw, PL RLD is called "Pigalak". From French Pigalle.

Yes, one of my relatives (would be my Mom's cousin) served in FR on WW-II and he told me that they had a saying over there -- appropriate to this amplifier "Keep the red light burning". I think I was only 10 years old at the time, and I couldn't understand why my father was laughing.
 
6P14P-EV i.e. EL84 equiv, and not 6P15P as written before at 327V plate voltage and 10.7 cathode voltage only consume 56 mA. Vg2 is 289V. Is this right?

Are tubes out of specs because they NOS or OS or are Va - Vg2 incorrectly set?
Can you provide characteristics of Ia as a function of Vg2 and Va? I have searched the internet with no luck.

According to datasheet 6P14P Ia should be 48 +/- 8 mA.
 
jackinnj said:
One piece of FR4 -- there are horizontal and vertical cuts so that the board can be split into 4 pieces -- a driver board, a LED array and 2 output boards -- looks like it is 9 x 7.5"

Really nice work.

(BTW, it looks like you need four more holes to be able to mount the LED array sub-board separately.)