I see on E-bay many sellers stock your products.
Are all these genuine?
Where we can find for sure?
Am I missing something? The schematic kept showing 3EF with 4 pairs of output transistor, but the picture of the pcb kept showing two pairs.
Is that a pcb that you buy and build?
Is that a pcb that you buy and build?
This was asked early in the thread and you can probably see that extra devices can be fitted below the board - as required. See posts #1-14.
Ha ha!!! I must be blind!! I still did not see it reading 30 posts from the first.
Anyway, you mean they just parallel another transistor onto the original 4? If so, won't that be dangerous of oscillation and/or current hogging as they share the same base stop and emitter resistor.
I haven't tried these with 4 pairs of output devices but I think LJM knows what he is doing and would have tested or at least been made aware in other forums and Facebook with builder's comments so far. Note the slower, cheap 15 MHz KEC version output devices used here: http://www.kadelectronics.com/ebay/L20-1.jpg
Why is this circuit so popular, other than the 3EF that provide higher impedance to the VAS, this is just basic Blameless design with no cascode LTP and no darlington VAS.
No simple parallel connected transistors. There are 8 emitter resistors on the PCB. So the special mounting is only for space savings.
Sajti
B: yes. This is a very simple structure.
It can make the transistor, closer with the voltage amplification signal pipe.
A shorter distance of wire
This higher frequency more stable work.
Dear ljm,
I'm intersted in this module. Can you please let me know which module revision has better audio performance (rev. 7 with bipolar, rev. 9 with Toshiba FET) and recommend a vend or for it ?
I wil drive b&w cm9 speakers.
Is 300VA per channel enough for 8ohms ?
Is +-50V better than +-65V for audio quality ?
I'm intersted in this module. Can you please let me know which module revision has better audio performance (rev. 7 with bipolar, rev. 9 with Toshiba FET) and recommend a vend or for it ?
I wil drive b&w cm9 speakers.
Is 300VA per channel enough for 8ohms ?
Is +-50V better than +-65V for audio quality ?
I have the L20SE...is possible add 1 pair more of exit transistors and use +/-65V? how much power in 8 and 4 ohms?
Hello,
Last year, i build a stereo amplifier with 2 l20se kit
2x36vac 500va écorce transformer + 2x10000uf 80v
No hum 👍😊
I'm very happy with sound 😍
Now i want build a mono btl amplifier with my mixer symétrique outpout
2x40vac 620va transformer + 4 x 10000uf 80v
I read is it possible to switch 1943 5200 by mjl21195 96 ( better soa )
Dear ljm are you ok with this and 0.33ohm émetor resistor ??🤔
Last year, i build a stereo amplifier with 2 l20se kit
2x36vac 500va écorce transformer + 2x10000uf 80v
No hum 👍😊
I'm very happy with sound 😍
Now i want build a mono btl amplifier with my mixer symétrique outpout
2x40vac 620va transformer + 4 x 10000uf 80v
I read is it possible to switch 1943 5200 by mjl21195 96 ( better soa )
Dear ljm are you ok with this and 0.33ohm émetor resistor ??🤔
Hello,
I change my choice, yesterday i buy a l20 version, the specs say 300w 55v. 350w 60v
Why my homemade transformer it Will be a better choice for my woofer amplifier project.
I change my choice, yesterday i buy a l20 version, the specs say 300w 55v. 350w 60v
Why my homemade transformer it Will be a better choice for my woofer amplifier project.
B&W
how did your project go? I have similar speakers B&W CM8 and considering using L20 V 9.2 boards.
how did your project go? I have similar speakers B&W CM8 and considering using L20 V 9.2 boards.