I had 8 6528A and 18 6528. I buy them just for OTL. but soon I found it not suitable. In Taiwan the weather is so hot . If i put it in my living room. It will be very terriable. So I want to make an AMP SE or SEPP will be fine. which tubes for 6528 seAMP will be better. I have 2 RAYTHEON 5842 some 5687 12av7 12b4a 6s4a 6c4 5844 5965 7898 6gk5 6er5 6j4 6j6 7062 ec86 6H30pi 6c45pi 5670 7b6 12sl7 12AT7 12au7....... or someone can give me an idea how to make a better SE-AMP.
The fan is a clever idea. The one OTL I built with 6528 required rather noisy forced-air cooling- they run HOT. There's 30 watts of heater power to dissipate before one even considers the plate dissipation.
One other thing is the criticality of warm-up time. The heaters must be run for at least 30-45 seconds before application of B+.
On the bright side, the tubes do make a lovely tinkling sound during warm-up and cool-down.
One other thing is the criticality of warm-up time. The heaters must be run for at least 30-45 seconds before application of B+.
On the bright side, the tubes do make a lovely tinkling sound during warm-up and cool-down.
Thanks I just Order with Amazon. I had made one 5842 DC 7236 with VT(RCA 5R4GYB) regular and 1(RCA 6AS7G)pass + 1RCA 6SQ7 1RCA 0A3 1RCA 0D3. The same problem with it(ALL the tubes sets to closed esp 7236 5R4 6As7G 5842). So I use an Fan for coolling. It works but a little bit noisey. And I think the fan will vibrate all the tubes.
Has anyone built the morgan jones SE amp?
I found a few of these puppies NOS at my local surplus store for $15 each.
I have been searching and the only information I find is the reference to the morgan jones SE amp but have not seen any other reviews about the design. Morgan Jones uses a 6j5 for the driver. By looking at the 6528 curves i can see that the tube is not the most linear. Can somebody recommend any other driver tube that maximizes the harmonic cancellation in the output tube?
Has anyone built another SE design for the 6528?
Or is the only hope for this tube a PP configuration?
Alfredo
I found a few of these puppies NOS at my local surplus store for $15 each.
I have been searching and the only information I find is the reference to the morgan jones SE amp but have not seen any other reviews about the design. Morgan Jones uses a 6j5 for the driver. By looking at the 6528 curves i can see that the tube is not the most linear. Can somebody recommend any other driver tube that maximizes the harmonic cancellation in the output tube?
Has anyone built another SE design for the 6528?
Or is the only hope for this tube a PP configuration?
Alfredo
I haven't built one, but I've heard it (the original) on the Arpeggio speakers. It sounded to me like most other DHT amps- easy to listen to with simple material, but clogs up when the musical textures are dense and/or the volume starts getting higher. After spending most of an evening with it, we switched over to some 2A3 push pull amps (DHT Rob) and never went back.
The 6528 is an amazingly good tube, though, if you respect its needs. $15 each is a real bargain, congratulations!
The 6528 is an amazingly good tube, though, if you respect its needs. $15 each is a real bargain, congratulations!
Thanks Sy,
Maybe PP is the way to go. I found a 10 amp 6.3v transformer locally at Allelectronics for less that 20 dollars. My preamp puts out up to 10V Rms so it might drive the a Class A PP enough to drive my 99 full range db speakers nicely. Maybe will try the LM317 self split and keep the path as short as possible. I also have a couple of 8K:8 Edcor transformers that a bought for a project i never built. This may do nicely.
Alfredo
Maybe PP is the way to go. I found a 10 amp 6.3v transformer locally at Allelectronics for less that 20 dollars. My preamp puts out up to 10V Rms so it might drive the a Class A PP enough to drive my 99 full range db speakers nicely. Maybe will try the LM317 self split and keep the path as short as possible. I also have a couple of 8K:8 Edcor transformers that a bought for a project i never built. This may do nicely.
Alfredo
Not a successful design, then.
John
I think I have to agree since I build only SE amplifiers, and none of mine are any worse in that regard than the PP amps they replaced..
Not a successful design, then.
John
No, it wasn't. It sounded like every other SE amp I've listened to.