2. amps-preamps
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What will raising the Va of atransformers provide?

I have a dual-mono custom built solid state power amplifer with a pair of 500Va transformers. The power supply is in a separate chassis/housing.

Is there any merit to increasing (upgrading) to upwards of 1000Va transformers? What kind of sonic benefits can this provide?

I realize in my lay understanding of amplifer design that this retrofit will likely require a cascading change-out of other components (resistors, etc.) as their requirements will have to be matched to the higher Va transformers.
If so, what are some examples of the better quality manufacturers? I am not concerned about price.

Scott
scott_wolff
atmasphere's avatar
atmasphere
11,662 posts
 
The intent with this Q & A is to [hopefully] make sure I'm not leaving anything on the table when it comes to getting the fullest reproduction available.

Well heck, you could try out some tubes in that system :)
scott_wolff OP
19 posts
 
Response to Magfan - System is on a dedicated 20a circuit with 12ga solid core wire. Current amp is standard Class A/B design, V-caps, 14ga solid core silver internal p-t-p wiring. Speakers efficiency is 90db+ (conservative). Listening is largely on weekends. Music is jazz, big-band, rock, blues, piano, electronic (Eno, Bob Holryd, Harold Budd, John Hassell, etc.)

Scott
scott_wolff OP
19 posts
 
Dcarol,

Thank you very much for your information sent 9.13.11. I agree with your response and will make sure my amp builder is on top of the rectifer & filter cap aspects (I'm reasonably sure he probably knows, but I'll talk to him nonetheless).

I've narrowed down the selection to a pair of Plitron 1500Va's. Their being potted and and being "low noise" are what sold me. After much research it appears they've got a reputation for quality. This is not to nay-say anything of the other manufacturers out there but I am comfortable with the decision. The challenge now is to try and avoid musical DT's for however long the build will take....

Thanks again.

Scott
magfan
1,583 posts
 
A household circuit is rated for something like 80% of capacity for full time use and only short term @100%.

I don't know rule-of-thumb, but a total of 1000va of transformer will put out a BUNCH of power continuously and still allow dynamic peaks....which are at least 10db and frequently higher than the average level.
Doesn't 10db amount to 10x the power?
Unless you have a HIGHLY reactive speaker, chances are you are playing electrical games with yourself.

Speaker 'efficiency' will be expressed as a percentage. Of power turned into sound, while Sensitivity is the 'db per watt', which also is related to impedance since a watt (voltage measure) is different at different impedances.
Somebody straighten this out if I've made a hash of it.
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