I've got the opportunity to get some output transformers wound by a friend (who I believe knows what he is doing!)
This would be the start of a poweramp project which could go two ways: a pair of 211's or four EL34 triode strapped.
I presently run a pair of EL34's in "triode" which sound great although they struggle to drive my Olsen Ariels as the output transformer is not wound for 4ohms.
I don't want to lose the delicacy and poise of the present set up and am concerned that 211's would spoil the party, although the extra grunt would be welcome.
Any words from the wise out there?
This would be the start of a poweramp project which could go two ways: a pair of 211's or four EL34 triode strapped.
I presently run a pair of EL34's in "triode" which sound great although they struggle to drive my Olsen Ariels as the output transformer is not wound for 4ohms.
I don't want to lose the delicacy and poise of the present set up and am concerned that 211's would spoil the party, although the extra grunt would be welcome.
Any words from the wise out there?
I hardly think a well executed 211 design is going to have less detail than a trioded EL34. Certainly my experience with 813 and GM70 suggests it won't. But in the end, it's all down to how well you do it, both in terms of the circuit and execution.
Personally, I'd go with the 211's, but I like big glowing bottles.
Big caveat though. You'd better be really confident with high voltage design and safety before you tackle a project like this. Both designs are going to be lacking in inner detail if you're dead.
Personally, I'd go with the 211's, but I like big glowing bottles.
Big caveat though. You'd better be really confident with high voltage design and safety before you tackle a project like this. Both designs are going to be lacking in inner detail if you're dead.
With the same transformer??
Seems to me that the 211 requires much more voltage and has a substantially higher plate impedance?
If you are expecting to run the primaries of the same output iron that you are now paralleling to get the plate impedance of 2 EL34s per side run in triode and running them in series to get the higher plate impedance, ur in for a surprise. The transformer will not likely work as well with the higher impedance set up in the primary.
Generally speaking, lower ratio output iron can be made to work better with less care and less interleaving, etc...
It also generally takes a larger bit of iron to run a pair of 211s in P-P than it will to run 4 EL-34s. Also the primary inductance will have a big effect on the bass response.
Maybe 4 x 300B in P-P??
Easier to execute.
But the 211s in P-P class A is a nice, but *big* amplfier physically, requiring a large high voltage supply - which as was noted is a good way to get dead quickly if you make a mistake. Just one.
Choose wisely, Luke Skywalker!
_-_-bear
Seems to me that the 211 requires much more voltage and has a substantially higher plate impedance?
If you are expecting to run the primaries of the same output iron that you are now paralleling to get the plate impedance of 2 EL34s per side run in triode and running them in series to get the higher plate impedance, ur in for a surprise. The transformer will not likely work as well with the higher impedance set up in the primary.
Generally speaking, lower ratio output iron can be made to work better with less care and less interleaving, etc...
It also generally takes a larger bit of iron to run a pair of 211s in P-P than it will to run 4 EL-34s. Also the primary inductance will have a big effect on the bass response.
Maybe 4 x 300B in P-P??
Easier to execute.
But the 211s in P-P class A is a nice, but *big* amplfier physically, requiring a large high voltage supply - which as was noted is a good way to get dead quickly if you make a mistake. Just one.
Choose wisely, Luke Skywalker!
_-_-bear
Bear,
I would not entertain using the same transformer for both topologies. It's just the opportunity to make something is there!
10 joules of any HT is bad for your health, I regard all valve circuits as extemely dangerous. I'm just curious to hear what people think of the sound of 211's.
I have to admit that I'm slightly prejudiced against 300B's. They can sound wonderful but never seem to have enough juice to get the music really moving from what little I've heard, also 4 a side are pricey and that money might be better spent elsewhere in the amp.
I would not entertain using the same transformer for both topologies. It's just the opportunity to make something is there!
10 joules of any HT is bad for your health, I regard all valve circuits as extemely dangerous. I'm just curious to hear what people think of the sound of 211's.
I have to admit that I'm slightly prejudiced against 300B's. They can sound wonderful but never seem to have enough juice to get the music really moving from what little I've heard, also 4 a side are pricey and that money might be better spent elsewhere in the amp.
Little experience with the 211's, more with 845/813, but the big DHT's can sound excellent, better than about all IDHT trioded pents/tets ime. But it's still a big "it depends" on implementation/design.simon dart said:
I'm not real keen on 300Bs, but if you need more herbs to get your system up and boogie-ing, the 211's might not be a big difference. Power output should be roughly equivalent (within a dB or three ottomh) and the big DHT's have more presence to the sound that belies the wattage. I'd still be using my big amps if I needed the watts.
The final cost of a 211 amp could easily be the same as a 4x300B when you factor in all the other costs for good HV parts.
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