Primrose(SumR Audio) Toroid GB

[bk856er]

Can we get a dimension spec on the encapsulated 400VA unit?

BK

 

[buzzforb]

Here you go.

 

[bk856er]

Thanks! Interesting - same dimensions +/- encapsulation. Was expecting the fully encapsulated version to be somewhat larger.

I use SumR encapsulated trafos for headphone amps (need quiet) and they are great. My understanding is that as a final step they go into a polymer can that gets filled with liquid epoxy and cured solid.

Planning to use one for an F6.

BK

 

[luvdunhill]

Looks good. I'd be up for the RC0400 922 4, but with dual primaries. Almost hard to believe those dimensions though.

Antek with similar specs is 125mm x 79mm, non-potted.

SumR with similar specs is 135mm x 70mm with potted and 120mm x 58mm without.

Can you verify one more time the dimensions?

 

[labjr]

Looks good. I'd be up for the RC0400 922 4, but with dual primaries. Almost hard to believe those dimensions though.

Antek with similar specs is 125mm x 79mm, non-potted.

SumR with similar specs is 135mm x 70mm with potted and 120mm x 58mm without.

Can you verify one more time the dimensions?

Maybe SumR uses higher quality steel core which enable smaller dimensions.

 

[RKH]

I added 2 transformers (2 x 25v secondaries at 400VA) and my original order

+ shaded myself green.

Ryan

 

[Lo_Tse]

I'll send invoices once I get confirmation of interest. Probsy will wait till next week, as kits are being packed at the moment as well as testing of store F5T boards.

Hey, store F5T boards, the last missing link

Does it mean that the boards will be available real soon?

Regards,

 

[buzzforb]

I believe so.

 

[sts9fan]

Hey, store F5T boards, the last missing link

Does it mean that the boards will be available real soon?

Regards,

Hahahahaha riiiiiight.


So what is the ordering time frame for these transformers? What is the manufacture lead time?
Do the encapsulated ones have full steel covers with mounting hardware?

 

[buzzforb]

I am running final test on store boards this weekend. If all checks out, Variac will release at his discretion, bu ti believe that translates into, very soon. Ill check with Richard on toroid time.

 

[PMI]

This may be a stupid Q, but looking at what other people specified, do I need to state 115/230V primary explicitly in the spreadsheet??

 

[buzzforb]

When asked the question, this is what Richard said.

The 50Hz group of 230Vprimary, may want a single primary. This is the group I was referring to.
However, if your North Americans want a single primary, now is the time. ( either 117V primary or 120V primary @ 60 Hz).

Richard

I like the idea of a single primary for no other reason than wire count, but it has to be specified up front.

 

[PMI]

Guess I missed that memo, sorry. I'm fine with the conventional 60Hz, 115/230 primary, thanks. Better to have more flexibility in case I ever "re-purpose" the transformer (chuckle).

 

[sts9fan]

Single primary/dual secondary is the way to go.

 

[buzzforb]

Guess I missed that memo, sorry. I'm fine with the conventional 60Hz, 115/230 primary, thanks. Better to have more flexibility in case I ever "re-purpose" the transformer (chuckle).

It wasn't posted before. I just wanted to post his exact response, as I had just asked him the question.

 

[Lo_Tse]

When asked the question, this is what Richard said.


I like the idea of a single primary for no other reason than wire count, but it has to be specified up front.

Pardon me for the newbie question - what are the differences (in terms of performances or otherwise) between a single and a dual primary, apart from less wires to deal with?

Thanks!

Regards,

 

[buzzforb]

I can't say that I know. Flexibility is the main advantage, I think.

 

[labjr]

Is there a difference between 117v and 120v primary?

 

[buzzforb]

Mine tends to be in 117 region. Depending on AC value in your home, you might get slight shift up or down on secondary rail.

 

[PMI]

Is there a difference between 117v and 120v primary?

In theory, there would be a small difference in the number of wire turns. Basically, it is SUPPOSED to be the AC voltage required to produce the nominal output @ specified load. So, (again in theory only), a transformer which can produce the specified output at a lower input voltage (115 or 117) would have been rated more conservatively than one which requires the input AC voltage to be 120 for the same output.

In practice, if you do your own testing, your results may not reflect the manufacturer's specifications, and for DIY audio, it may be pretty meaningless.

For something like an industrial/commercial product, it may be critically important. For example, you may want to know that your product will function when the customer who purchased it switched to emergency power to keep a line running, or shut it down in orderly fashion. In high speed offset printing, one sagging power supply could cause a $50,000 loss on a single line (something that has actually happened). On a rolling mill, it could kill an operator.