Hi forum. This is my first post. But I have visiting this site for a while and like it a lot. My problem is that I don’t know what will be my next Tube project. I’m sort of experienced and have built a couple of useful heaters 😉 but now I want to build something more powerful than SE. PP or parallel is in interest. Monoblocks will also be preferred. I have built with Lundahl transformers before and like them a lot so preferably go for those again. But I haven’t used 300B tubes and would like to build with them sins I have heard a lot about them. I have tried to pick a project to build but haven’t found anything suitable. Feel free to convince me to build something else too just for the reason it’s a better Tube amplifier. Because simplicity and quality/performance is on topic and off course a very useful high-end amp.
Thanks // Kalle G
Thanks // Kalle G
@artosalo PP with 300B is probably not a good solution ,but Parallel SE could be a solution to get enough power for regular speakers. If you as in my case want to use 300B.
What about this solution?
300B parallel single-ended tube amp | audioroot
I think it could be a good compromise to power/gain, high fidelity and straightforward build...
I have no experience to build with coupling transformer but Think it could be nice. Any opinions?
What about this solution?
300B parallel single-ended tube amp | audioroot
I think it could be a good compromise to power/gain, high fidelity and straightforward build...
I have no experience to build with coupling transformer but Think it could be nice. Any opinions?
Why not if the below quote from that article were even nearly true:
"The amp uses two tubes in parallel, which makes it easy to produce 30 Watts of clean and wonderful single-ended 300B power!"
With given values the amplifier can put out max. 20 W with high distortion (about 6 %).
Not so wonderful to me.
In general, if you require 30 W or so, the PP amplifier would be much, much cheaper.
Last edited:
PP 300Bs disposes of the (IMO) excessive 2nd order HD the type produces Lynn Olson has done some nice things with PP 300Bs.
BTW, both cost and weight strongly favor acquiring PP O/P "iron".
BTW, both cost and weight strongly favor acquiring PP O/P "iron".
Parallel 300B SE is fully OK, but 30 W is not available, if this is important to you.
I would have higher load impedance and thus essentially lower THD, with just slightly lower max. output power.
I know that one 300B / channel (~8 W) would be in practice more than sufficient for me
with these speakers: Giant FS-100N | VEF Radiotehnika RRR
I would have higher load impedance and thus essentially lower THD, with just slightly lower max. output power.
I know that one 300B / channel (~8 W) would be in practice more than sufficient for me
with these speakers: Giant FS-100N | VEF Radiotehnika RRR
Yes, I don’t need 30W but could certainly need more than 8. I have speakers with sensitivity 90dB and tube amp with ca 8W but would love to be able to also load any normal regular speaker. And I’m open to go for any PP or parallel with really good quality sound.
Allen Wright's PP2C would be ideal. Push-pull triode-wired KT88s. The schematic is floating around the web. The schematic of the simpler, EL34 based PP1C is on the Vacuum State website. He used Lundahl transformers for all his amps.
The quote of Allen's I keep coming back to: "I want speed and I want definition." If you want a warm, soft amp look elsewhere!
The quote of Allen's I keep coming back to: "I want speed and I want definition." If you want a warm, soft amp look elsewhere!
I don have a schematic. I have looked around and figured out a design. Mostly its a design by Lars Ohlsson also called RimboLasse. I can make a schematic if you like?
I've always liked the look of GaryW's PP 300B amp in post # 4 in this thread. Never heard it, but I plan on building a variant of it if I ever get the time. Even has glow tubes.
300B push pull amp
Not as nice as Lynn Olson's Karna, but a heck of a lot easier to implement and a LOT less iron.
I recently found zigzagflux's PP 300B here; post #28, power supply later. A lot more going on here, though.
Two driver options for 300B push pull
300B push pull amp
Not as nice as Lynn Olson's Karna, but a heck of a lot easier to implement and a LOT less iron.
I recently found zigzagflux's PP 300B here; post #28, power supply later. A lot more going on here, though.
Two driver options for 300B push pull
Last edited:
I can promise good performance, but not a sound that you definitely like.
I am not one of those wizards that can promise this.
I have built fixed biased PP (UL and pentode mainly...) amplifiers with different sort of output tubes with the following
voltage amplifier / phase inverter circuit. This is a Dynaco-style front end with soviet made 6F12P triode-pentode.
I have tested circuits for at least the following output tubes:
6V6, 6L6, 807, 6P3S, 6P9, EL84, EL86, EL34, JJ EL509, 6P41S, QQE03/12, 12E1 and maybe some more...
The power level of the above list covers from 10 W to 100 W.
Just let me know what tube type you prefer and I show the complete schematic (or as much as I have).
Attachments
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.