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Why do so few low power amplifiers using 300B have balanced inputs?

I was wondering if someone would kindly explain to me why so few lower powered 300B amplifiers in SET, PSE, or PP configurations offer balanced inputs.  Thanks to all respondents in advance!

As a less important question, are there still amplifiers out there that use the 300BXLS triode to its full 20 WPC potential....hard to find as I have some NOS KR 300BXLS I acquired some years ago.  Thanks so much!

audiobrian
erik_squires
16,395 posts
 
Depends on the adapter. ;) Putting an active stage or transformer at the amp end will do a pretty good job.  However, are yo sure there's something that needs fixing? 5m might be fine with shielded, single ended cables. Maybe. Worth trying first.

If you need transformer coupling, look up Jensen transformers, they have some great devices to do this for you.

Best,

Erik
stringreen's avatar
stringreen
6,486 posts
 
A truly balanced circuit is like having 2 completely different circuits ....one for the + side, and one for the - side. This is a very expensive piece to build. Tube circuits are expensive to begin with....this would about double the cost. Designers aren’t sure the upgrade is worth the cost on the battlefield of sales.
czarivey
5,946 posts
 
I share the same thought stringreen,
Those low-powered 300b single tube per channel amps can’t by any means be fully balanced. The can however have as previously mentioned a differential input stage.
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