why reinvent the wheel?
simplify and repackage the circuit. Replace all caps etc, don't bother with the EF86 and the 12ax7 as they are only there to provide gain you no longer need. Keep the existing ECL82. Or, if you want a bit of a fun challenge, RH84 the circuit. Values will have to be modded a bit, and revintage will tell you you are mad, but you have all the bits...
simplify and repackage the circuit. Replace all caps etc, don't bother with the EF86 and the 12ax7 as they are only there to provide gain you no longer need. Keep the existing ECL82. Or, if you want a bit of a fun challenge, RH84 the circuit. Values will have to be modded a bit, and revintage will tell you you are mad, but you have all the bits...
original diagram here
but it shows a slightly different tube compliment to what you have.... http://mb.abovenet.de/tonbandwelt/philips/el3536/el3536.htm
but it shows a slightly different tube compliment to what you have.... http://mb.abovenet.de/tonbandwelt/philips/el3536/el3536.htm
Re: original diagram here
Thank you aardvarkash! This, once again, goes to show that this website is a real treasure. For days I had been unsuccessfully searching the net for the original diagram...
I wanted to take a look at the schematic in the first place in order to find an info on the output transformers - 3.5 Ohm speakers were connected and that's what confused me... Since I'm new to tubes and without any diagnostic equipment whatsoever (save for a cheapo digital multimeter), I couldn't measure the primary load...
Further, it turns out the mono RtRs were not EL3536 after all (I was careless enough to throw the decks away without writing down model numbers). They have EL3536 output transformers - WT 511 22, but the power transformers are WT 510 92 and WT 511 13.1 - different numbers but with identical pin layout and both with EZ80...
Another model, though - EL 16B, perfectly matches the parts layout...
And as to the RH EL84 - I've built one and I'm extremely satisfied with it. Hammonds, no PIOs and no tantalums and it still sounds quite nice...
Thank you aardvarkash! This, once again, goes to show that this website is a real treasure. For days I had been unsuccessfully searching the net for the original diagram...
I wanted to take a look at the schematic in the first place in order to find an info on the output transformers - 3.5 Ohm speakers were connected and that's what confused me... Since I'm new to tubes and without any diagnostic equipment whatsoever (save for a cheapo digital multimeter), I couldn't measure the primary load...
Further, it turns out the mono RtRs were not EL3536 after all (I was careless enough to throw the decks away without writing down model numbers). They have EL3536 output transformers - WT 511 22, but the power transformers are WT 510 92 and WT 511 13.1 - different numbers but with identical pin layout and both with EZ80...
Another model, though - EL 16B, perfectly matches the parts layout...
And as to the RH EL84 - I've built one and I'm extremely satisfied with it. Hammonds, no PIOs and no tantalums and it still sounds quite nice...
Can anyone post a diagram of an EL16B as I have similar power and output transformers. My transformers are wt 510 92.1 and my out put has the number wt 511 21.
...and keep the mustard Philips/Mullard capacitors if you can, guitar amp makers go crazy for them.
Thank you for comments and schematic.
I have found this missing capacitor on schematic diagram.
I have found interesting link on how to measure output transformer impedance:
Output Transformer Impedance
Is one EL84 will provide enough gain?
Should I add EL82 (first stage) to this amplifier?
Best regards.
I have found this missing capacitor on schematic diagram.
I have found interesting link on how to measure output transformer impedance:
Output Transformer Impedance
Is one EL84 will provide enough gain?
Should I add EL82 (first stage) to this amplifier?
Best regards.
Good evening, I have follow instruction on the previous link and calculated inpendance
for Philips transformers WT 511 22:
Turns ratio - 38 : 1
For a 4 ohm load - 38x38x4=5776 ohms.
Best regards.
Sasha.
for Philips transformers WT 511 22:
Turns ratio - 38 : 1
For a 4 ohm load - 38x38x4=5776 ohms.
Best regards.
Sasha.
Hey, the attached pic is a Hartley oscillator! Screen and Vbb are interchanged, creating positive feedback! Or OK if you want to make a siren 🙂
Primary self inductance is 6H so you need some FB for anything decent below 80Hz.
See attachment, HV goes to "B", G2 goes to "E", anode to "C". C-D has 170R resistance.
Attachments
This is an old trick, usually done to save a few pennies.
The main B+ has ripple buzz. Some of this passes through the output transformer to the speaker.
The small sub-winding (only a few percent of the total) also has the ripple buzz. This is injected in opposite phase to the power tube screen and driver plate circuit. This acts in opposition to the ripple flowing to the speaker. If everything is carefully proportioned, the two ripple paths "cancel". The main power supply can be reduced from say 40uFd-Choke-40uFd, to just one 60uFd, with great savings of cost.
Unless you build that exact plan, the cancellation won't be even close. Since you can't run a lot of tests and custom wind a transformer, what DIY folks do is just start from a clean main B+ (big-uFd caps and a small resistor or choke).
There is an important capacitor missing.Is on the left part of the schematic.
Mona
Attachments
Why is that? I have a few of them in my component cabinet.
Mostly 400V dc operating voltage.