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Post by timjthomas on Dec 1, 2017 18:43:56 GMT
Any benefits, or perhaps better said pro/cons, to all tube amplifier vs hybrid?
What about those designs that use point to point wiring ("hand made") vs. those that use PCBs?
(As you can tell I'm not an electrical engineers.)
Thoughts / comments?
Update
- I should have done some searching - there are a number of webpages that talk about this. Interesting reading. Looks like it comes down to the competence of each design, rather than the approach chosen.
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solderdude
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Post by solderdude on Dec 1, 2017 19:39:11 GMT
yes, the latter.
Not only the schematic but more how things are implemented in real life, component choices, wiring (how wiring actually runs) and above all the reference (the ground signal).
Hybrid can supply more output power and does not need transformers to drive low impedances.
Tubes behave more linear on higher voltages (they were designed for high voltages) but this is nullified again by transformers which convert the high voltage swing to a low voltage swing again.
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Post by flacman on Feb 14, 2018 11:05:20 GMT
I heard that the tube responds better, because the electron moves in the vacuum and less error in the "vacuum" material.
Tube "fans" always try to get as many tubes as possible into their designs.
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solderdude
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Post by solderdude on Feb 14, 2018 13:14:52 GMT
I heard that the tube responds better, because the electron moves in the vacuum and less error in the "vacuum" material. Tube "fans" always try to get as many tubes as possible into their designs.  |
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Rabbit
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Post by Rabbit on Feb 15, 2018 9:25:22 GMT
Perhaps a denser vacuum slows the electrons down?  |
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Post by lobalwarming on Feb 16, 2018 21:55:54 GMT
Perhaps a denser vacuum slows the electrons down? But...with slow and steady electrons, those slow smoky romantic ballads linger longer on the lobes. |
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Post by flacman on Feb 17, 2018 15:42:28 GMT
Perhaps a denser vacuum slows the electrons down? But...with slow and steady electrons, those slow smoky romantic ballads linger longer on the lobes. I think the defects in the solid materials are the main reason. |
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solderdude
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Post by solderdude on Feb 17, 2018 21:29:31 GMT
Perhaps more fluids are needed ?
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Post by lobalwarming on Feb 17, 2018 21:54:23 GMT
Perhaps more fluids are needed ? Probably the secret to the liquid midrange that we thirst for. |
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Post by ronzo56 on Feb 18, 2018 1:32:51 GMT
Perhaps more fluids are needed ? Probably the secret to the liquid midrange that we thirst for. But not too much for the older crowd. They won’t sleep through the night. |
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Post by lobalwarming on Feb 18, 2018 20:34:41 GMT
Probably the secret to the liquid midrange that we thirst for. But not too much for the older crowd. They won’t sleep through the night. Frans has a mod for that. Clip-on hearing bladder aids. With adjustable moisture control - turn it up to 9 and your vintage tubes will sound as arid as the best worst SS amp - dry, flat and lifeless. A level of boring that only the fully-caffeinated could stay awake for. |
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Post by Mr Trev on Feb 19, 2018 2:45:01 GMT
Forgive me for jumping in with a serious question (I'll try to make up for it with a unquestionably flippant remark at a later date)
I've read quite a few comments that OTL amps just don't pair well with planar headphones. Any truth to that?
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Post by lobalwarming on Feb 19, 2018 4:16:18 GMT
Yes, there's truth to it.
Difficult to make a good transformerless output tube amp with a low output impedance. If the OTL amp has an output impedance of 50-60 ohms connected to a set of 300 ohm headphones, not a big deal. Want the output impedance to be lower than the driver impedance, ideally by a factor of 5-10.
Same amp connected to a set of planars with 35 ohm impedance, then it is an issue. The tube amp will struggle to deliver current when the music water has to run uphill to fetch a pail of dynamic crests at the bottom of the bass well. And professionally mixed musical metaphors lose top end bandwidth and drizzle out distorted versions of the mushy lower regions. ;-)
There's also the damping factor. That is the control the amp has on dealing with the back EMF created by the driver. More of an issue with speakers than headphones...usually.
However, some OTL designs have a reasonably low output impedance under 15 ohms. Those wouldn't be too compromised driving efficient 35ohm planars. The design topology and implementation as with everything else is where the details play hopscotch with the devil.
Traditionally, output tubes were isolated from voracious current appetites using a transformer to match the relative impedance mismatch. Really good, linear transformers are expensive tho, so tube amps with high quality trannies usually cost more than OTL amps.
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solderdude
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Post by solderdude on Feb 19, 2018 15:14:47 GMT
Basically that.
It largely depends on how loud one wants to play, headphone impedance and efficiency of the headphone.
You can replace the word planar with 'any low efficiency, low impedance headphone'.
Works great foor 300 to 600 Ohm headphones as they do not require much current.
Of course there are OTL designs that can even drive 8 Ohm speakers which would have no problems.
The output devices and produced heat as well as consumed power and price will all be big though.
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