@grataku
I agree with you..It doesn't make much sense to pay the extra money for a kit and then heavily modify it.
As it stands now, I am inclined to build Andrea Ciuffoli's 300B reference amplifier.
I am in doubt if I should build the 6 Watts SE or the 14 Watts PSE version.
I will probably end up building the PSE version, which is not much more expensive than the SE version, and should leave me with a bit more headroom.
I agree with you..It doesn't make much sense to pay the extra money for a kit and then heavily modify it.
As it stands now, I am inclined to build Andrea Ciuffoli's 300B reference amplifier.
I am in doubt if I should build the 6 Watts SE or the 14 Watts PSE version.
I will probably end up building the PSE version, which is not much more expensive than the SE version, and should leave me with a bit more headroom.
Kits are usually meant for people who otherwise would never undertake or finish the project. 90% of projects never gets built . I think I made an **** of myself here because I was commenting on AN factory products not ANK which are different thing although many people like them and they are OK for the money . I didn't check recently but I don't think they offer plain vanilla 6SN7 -300b circuit..Kit 1 is 6SN7 5687-300b and monos are transformer coupled so more in line with general thinking.
It is much better to build a p-p of 300B instead
with a good trnsformers, the results will be more interesting for different reason.
This is one my old stuff done years ago.
Walter
Attachments
There are OK; in the past was named Kit three, very good stuff.
Some test done
the freq response at 3 Vout/8 ohm, there are some indecision around 50 kHz but non very important; the response on bass i good.
Very interesting is the THD vs Freq
It is costant and reach the 0,5 % at more of 20 kHz; It is good results.
Walter
Walter
We're mixing factory AN and ANK - kits stuff here. Kits never had plain vanilla 6SN7 circuits. An factory units do. P3 is a power amp section of Meishu 300B stereo se amp . P4 is a pair of monoblocks using stereo P3 as a monoblock in PSE mode. Circuit is doubled from the gain stage . It is 6SN7 -5678-300b with separate power supplies for gain and power stages.
I mean always ( as wrote) Kit from AN who is UK.
And they are good for who want to find a simply but efficent stuff
The prices are secondary, as always in this case.
Walter
And they are good for who want to find a simply but efficent stuff
The prices are secondary, as always in this case.
Walter
Kits were never meant to beat production models. Which are ...?? Plain Vanilla cascade 6SN7 for most parts (old Meishu line excluded with P3, P4 amps).
I'm sure Kondo and Shindo amps measure poorly as well and almost all silver line of ANUK is an example of poorly measuring thievery. I hope their transformer coupled designs are measuring better.
If only those poor (actually rich ) Monkeys who buy those overpriced dildo's have Spectrometers and other proper equipment to check that stuff instead of listening we could get rid of those deceitful leeches in audio business.
I'm sure Kondo and Shindo amps measure poorly as well and almost all silver line of ANUK is an example of poorly measuring thievery. I hope their transformer coupled designs are measuring better.
If only those poor (actually rich ) Monkeys who buy those overpriced dildo's have Spectrometers and other proper equipment to check that stuff instead of listening we could get rid of those deceitful leeches in audio business.
Andrea Ciuffoli parallel single ended is a big project! 🙂
My 300b is 9W autobias, 3.5k OPT hashimoto, 455V B+ 1kohm/90uF polypropylene cap cathode bias and Rod Coleman heater. The input tube is a 3$ sharp cutoff pentode with 10M45 CCS and 300V B+ sim 0.17% input stage distortion. Sounds dead quiet, no hum whatsoever & coming from solidstate amplification it's a huge level up!
I am planning to build the TubeLab 300b with fixed bias and mosfet driver next year.
People call a 300b amp a "DHT" amp, but that only refers to the output stage. In all my DHT amp building I have found that the most important place to put the DHT is in the input, not the output. So my input tube is a 26. Get the sound right from the start. My outputs are EL12n in triode, mu=18, so I have a simple 2-stage amp with plate dissipation of 18W. I always prefer 2 stages to 3 stages - cleaner and more immediate sound. But if you want to use a 300b then only use one 6SN7 driver stage and make the input tube a 26 or a 10Y. Or have 2x DHT input stages. That will probably have as much effect on the sound as the OPT.
Always DC heating, filament bias. Rod Coleman regs, see Lyrima. Details and schematics on the #26 preamp thread
Andy don't forget, cathode filament bias resistor and anode resistor or choke loaded. Merry Xmas
< Andy don't forget, cathode filament bias resistor and anode resistor or choke loaded. Merry Xmas
Correct! And Merry Xmas to you too!
Correct! And Merry Xmas to you too!
Oh yeah baby! I am gonna buy a couple more regs from Rod then, they work like a charm.
Merry X-mas!
@grataku sounds like you build a nice amplifier yourself, how do you like it?
@andyjevans the amplifier I am planning to build is 2 stages with DHT on both stages.
The original design uses AC heaters, but I am thinking about using DC for the heaters instead. Should be no big deal to design a DC regulator for the heaters
@andyjevans the amplifier I am planning to build is 2 stages with DHT on both stages.
The original design uses AC heaters, but I am thinking about using DC for the heaters instead. Should be no big deal to design a DC regulator for the heaters
Why try and re-invent the wheel? Rod Coleman has been refining his regulators for over 10 years, and he's a very clever chap. I think his view would be that after 9 iterations (V9) it's a very big deal to get it exactly right.
How are you going to get enough gain out of 2 stages of DHTs? The usual suspects - 10Y, 26, 47 - have a gain of around 8. For 2 stages you would need a 1:4 step-up transformer on the input. That's perfectly possible and I have done it with a Hammond 1140-LN-C. Ale Moglia on Bartola Valves did it with a Lundahl transformer for his 300b design. There are some esoteric and expensive new boutique DHTs with more gain if you want to throw money at it. I've never used them.