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Question for our tube amp builders....


Coytee

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I'm asking more out of curiosity....  I keep telling myself I don't need a tube amp.....  don't need a tube amp.....

 

 

I read some things the other day and can't get this question out of my head.

 

For the sake of conversation, let's just say that tube amps are designed to play 20/20K.

 

What if you are biamping and don't need the amp to go to 20hz?

 

What if you are crossing at say, 300/500 (other) hz.  Can you skew the output such that you can maximize other benefits into the sound since the amp isn't expected to play as low?

 

If so, what are the other trade-off's that you can now explore?

 

(no particular amp/tube flavor in mind although since SET seems to be a popular flavor, we can use SET)

 

Would you simply use different iron?

Could you squeeze more output since the total output isn't spread so wide?  (make a 2A3 think it was a bad-azz KT-90??)

 

 

 

 

 

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I've had several SET amps and a pair of SE-OTL amps.

 

Though I liked the quality of the sound, I was terribly frustrated with the lower output.....I simply wanted more of what it gave.

 

That is in part what has me curious.

 

If a SET-300B gave me good sound but not enough, could a 300B designed for a more narrow output, provide more of it?

 

Also, since I'm using an active, it would be nice to have XLR inputs.

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You wouldn't necessarily get more mid band power. The real advantage is you can get away with much smaller output iron. When you airgap a transformer which is necessary when standing DC current is passing through the winding the inductance drops off. To compensate for a lower L output transformer designers use more turns to increase L. More turns means more copper and iron and this is why a 20-20k output transformer for SE tube amps are so expensive.

-Cindy

Edited by CindyJarvis
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You wouldn't necessarily get more mid band power. The real advantage is you can get away with much smaller output iron. When you airgap a transformer which is necessary when standing DC current is passing through the winding the inductance drops off. To compensate for a lower L output transformer designers use more turns to increase L. More turns means more copper and iron and this is why a 20-20k output transformer for SE tube amps are so expensive.

-Cindy

So in a sense one could cut down on cost per an amp but still have the sound quality.

Sent from my SM-N920P using Tapatalk

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Another benefit along with reduced cost is better high frequency range. When you use more turns to increase the primary inductance the downside is increased shunt capacitance which limits high frequency response. Designing transformers is a tradeoff. When you eliminate the low frequency response as a requirement you can have better high frequency response.

-Cindy

Edited by CindyJarvis
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Can Carl or any mod move this as per the above request?

 

That said....  he says with a mysterious voice....  just who is this Cindy Jarvis?

 

Pops up out of nowhere and has given some interesting comments.

 

Cindy....  care to introduce yourself to us?  (your background as you are sounding more like an engineer than a home maker (not that there's anything wrong with home makers that are engineers, in fact, I know one))

 

Your first 8 posts are not typical of a new person....  let alone, a female new person!!  We don't get too many women that hang out with us!  (where's Me Again when I need her...)

 

All above is in my opinion and I mean no disrespect with my curiosity.

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Hello, I found this forum through a google search about tube amps and klipsch speakers. My background is a B.S. in Mathematics. I also worked alongside some very bright engineers for my uncles corporation designing power supplies. I happen to have a passion for music like my mother.

-Cindy

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I'm asking more out of curiosity....  I keep telling myself I don't need a tube amp.....  don't need a tube amp.....

 

 

I read some things the other day and can't get this question out of my head.

 

For the sake of conversation, let's just say that tube amps are designed to play 20/20K.

 

What if you are biamping and don't need the amp to go to 20hz?

 

What if you are crossing at say, 300/500 (other) hz.  Can you skew the output such that you can maximize other benefits into the sound since the amp isn't expected to play as low?

 

If so, what are the other trade-off's that you can now explore?

 

(no particular amp/tube flavor in mind although since SET seems to be a popular flavor, we can use SET)

 

Would you simply use different iron?

Could you squeeze more output since the total output isn't spread so wide?  (make a 2A3 think it was a bad-azz KT-90??)

 

The output is determined by the output tube setup, not the transformer as an upper limit. Transformer quality doesn't increase just because it has narrow bandwidth, in fact, the reverse is generally true. Just look at the cheap little MI transformers compared to HiFi transformers. They are 1/4 the size, and have more distortion. If you could design a special transformer for the narrow band, then yes, you could improve it over larger ones, but the cost of doing that for a one off is kind of prohibitive. The small ones on the shelf will not likely be better than "full bandwidth" HiFi trannies. 

 

There's really not much to recommend designing a limited bandwidth amp.

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You wouldn't necessarily get more mid band power. The real advantage is you can get away with much smaller output iron. When you airgap a transformer which is necessary when standing DC current is passing through the winding the inductance drops off. To compensate for a lower L output transformer designers use more turns to increase L. More turns means more copper and iron and this is why a 20-20k output transformer for SE tube amps are so expensive.

-Cindy

 

 

Hey, it's great to see some ladies interested in the technology. Very pertinent post. It will be interesting to see a lady's POV here. 

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You wouldn't necessarily get more mid band power. The real advantage is you can get away with much smaller output iron. When you airgap a transformer which is necessary when standing DC current is passing through the winding the inductance drops off. To compensate for a lower L output transformer designers use more turns to increase L. More turns means more copper and iron and this is why a 20-20k output transformer for SE tube amps are so expensive.

-Cindy

 

 

Hey, it's great to see some ladies interested in the technology. Very pertinent post. It will be interesting to see a lady's POV here. 

 

 

Welcome to 2016 Mark.

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I guess I missed something.

 

Although I don't mind/care if Cindy is someone else....  I did/do have my suspicions that it might have been the case.  If she is someone and there were issues with them, I guess I totally missed the issues as I'm clueless as to some of the responses.

 

That said....  I suspected something amiss on her first post but didn't say anything.

 

 

Ok, no big deal on that, whatever the reality is.  I have no bone to pick with anyone.

 

So the upshot seems to be that if you build a tube amp with a more narrow range, you can simply get by using some less expensive parts and that's about it?

 

If you give it XLR inputs does that throw any wrenches into the works?

 

(why XLR?  because my active has them for outputs)

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