Hi!!
I want know what you think about that schematic. If there are some mistakes or if I could do something better please give me advise. And that grid resistor is 1k no 1R, my mistake.
THX
I want know what you think about that schematic. If there are some mistakes or if I could do something better please give me advise. And that grid resistor is 1k no 1R, my mistake.
THX
Hi Metalmaster,
Your schematic does not show...likely because it is to big in pixels...max is 800*600 and should not be bigger than 100k.
If you like you can send schematic to me and I will change and post it for you..
Regards,
Bas
Your schematic does not show...likely because it is to big in pixels...max is 800*600 and should not be bigger than 100k.
If you like you can send schematic to me and I will change and post it for you..
Regards,
Bas
Hi,
Actually I think it's 800*1200 and no larger than 100Kb but more importantly, if you preview your post the image refuses to attach.
Cheers,😉
Actually I think it's 800*1200 and no larger than 100Kb but more importantly, if you preview your post the image refuses to attach.
Cheers,😉
Hi,
If it we're me I'd drive a 300B with a 2A3, trioded EL34 or similar, or take an entirely different road.
Cheers,
😉
If it we're me I'd drive a 300B with a 2A3, trioded EL34 or similar, or take an entirely different road.
Cheers,
😉
Hi,
Hmmm...memory tape going bzzzzzzzzzzz and bzzzzzzzzzz...
Can be done though....
Came up with zip...but...I do recall the WE91 mods of La Maison de L'Audiophile...Good sounds...
Good recipe too, a penthode driving a triode...Hold on...Ahhh...Thorsten Loesch, our "dondersteen"...
Bingo:
Thunderstone Loesch..........
Hope that helps,😉
Hmmm...memory tape going bzzzzzzzzzzz and bzzzzzzzzzz...
Can be done though....
Came up with zip...but...I do recall the WE91 mods of La Maison de L'Audiophile...Good sounds...
Good recipe too, a penthode driving a triode...Hold on...Ahhh...Thorsten Loesch, our "dondersteen"...
Bingo:
Thunderstone Loesch..........
Hope that helps,😉
Konnichiwa,
First, you can likely drop that resistor.
Secondly, your +B supply will have some nasty resonances, you probably want either more capacitance or inductance, damping resistors and you really want to tune this, best done in the first place in P-Spice and then finetuned in the Amp.
Thirdly, your gainstructure is a bit problematic. Your input can step up by no more than 1:4 by which time reflected input capacitance is at a srathospheric > 1nF making a seriously meaty preamp mandatory. The 300B Driver has a Mu of around 3.85 and the IT will not do more than 1:2 sensibly, even that should probably not be used. With around 80V Bias you will have 2V input sensitivity for full Output using a 1:4 input and a 1:2 interstage stepup, both of which will limit bandwidth and 4V input sensitivity for no interstage stepup.
Also, for "sound" reasons, you might wish to use a 10/10Y/VT-25 or similar as driver. People who have tried have liked the 10 or also the WE 205 (Sakuma) as driver for a 300B over many other valves. The circuit can remain as before, except the heaters should be around 6.5 - 7.5V DC @ 1.25A. You get a Mu of around 8 and you can use a lower power Interstage Transformer with likely better bandwidth.
If you are going to use DC Heaters, how about making the symmetrical and filtered via emitter follower "gyrators" or inductors?
Sayonara
metalmaster said:
First, you can likely drop that resistor.
Secondly, your +B supply will have some nasty resonances, you probably want either more capacitance or inductance, damping resistors and you really want to tune this, best done in the first place in P-Spice and then finetuned in the Amp.
Thirdly, your gainstructure is a bit problematic. Your input can step up by no more than 1:4 by which time reflected input capacitance is at a srathospheric > 1nF making a seriously meaty preamp mandatory. The 300B Driver has a Mu of around 3.85 and the IT will not do more than 1:2 sensibly, even that should probably not be used. With around 80V Bias you will have 2V input sensitivity for full Output using a 1:4 input and a 1:2 interstage stepup, both of which will limit bandwidth and 4V input sensitivity for no interstage stepup.
Also, for "sound" reasons, you might wish to use a 10/10Y/VT-25 or similar as driver. People who have tried have liked the 10 or also the WE 205 (Sakuma) as driver for a 300B over many other valves. The circuit can remain as before, except the heaters should be around 6.5 - 7.5V DC @ 1.25A. You get a Mu of around 8 and you can use a lower power Interstage Transformer with likely better bandwidth.
If you are going to use DC Heaters, how about making the symmetrical and filtered via emitter follower "gyrators" or inductors?
Sayonara
I'm sure Lundahl will like it 😉
Why do you use such a small cap value after the first choke? I would probably use 50µF rather than 10µF. And if you use such small cap values (10 or 50µF), why not use paper or plastic caps rather than electrolytics?
Best regards,
Mikkel C. Simonsen
Why do you use such a small cap value after the first choke? I would probably use 50µF rather than 10µF. And if you use such small cap values (10 or 50µF), why not use paper or plastic caps rather than electrolytics?
Best regards,
Mikkel C. Simonsen
Resistor and +B will be not a big problem. I can give one more voltage on transformer (7V) becouse thats not big cost and it give some possibility to experimentation and education - that is my first tube amp. 
Im not sure what should I do with my gainstructure. That is my bigest problem 🙂
Im not sure what should I do with my gainstructure. That is my bigest problem 🙂
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