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by **Thinker1920** » Mon Sep 10, 2012 6:56 pm

Hi everybody,

I was just wondering if I changed my output transformers to higher quality ones if it would increase the amps freq. range? Iwas looking at the hammond output transformers and the cheaper ones say they only go down to 100 Hz and the $$$$ one's say they go down to 20 Hz. So considering my old motorola has outputs that look like the cheaper hammonds does that mean they only are going down to 100 Hz? and if so would changing them out for the more expensive ones increase the amps range?

Thanks, just curious

by **battradio** » Mon Sep 10, 2012 7:17 pm

More than likely if the Motorolas are metal incased they will go down to 50 to 40 hz , if they are paper who knows , if you want to go with beter transformers Ecor's would be cheeper .

How about a picture of your amp .

by **Geek** » Mon Sep 10, 2012 8:35 pm

NFB also increases an output transformer's capability by lowering the output tube's impedance, making the existing primary inductance have greater effect.

I always take spec sheets as a guideline.

Cheers!

by **Thinker1920** » Mon Sep 10, 2012 9:45 pm

they are paper, what's NFB? I believe the amp is a SH12N out of a motorola portable record player but I haven't been able to find tech specs on it beyond the fact that I think it's 4 watts.

by **battradio** » Mon Sep 10, 2012 10:01 pm

http://www.aikenamps.com/NegativeFeedback.htm

Find a beter amp to mod , you need a console pull at least to start with .

by **Thinker1920** » Mon Sep 10, 2012 10:18 pm

So I've tried to post a pic about 20 times with both IE and Firefox and I'm starting to go nuts

What's wrong with what I have? It has a good clear sound, just wanted to see if I could extend the range. and I like the S.E.T. amps and I haven't seen a lot of console pulls that are Single ended.

by **nyazzip** » Mon Sep 10, 2012 10:38 pm

i say spring for a nice output transformer and try it, and if you still aren't happy, then you will have an excuse to build yourself an amp
[:)

by **Thinker1920** » Mon Sep 10, 2012 10:42 pm

I was able to get it as a profile pic after about 30 tries

I have it setup with Klipsch Cornwall's the power cap's new and the coupling caps are new, the tubes are Tung Sol 12ax7's and Russian output's with a NOS RCA rectifier
I was under the impression that the Motorola amps were pretty good out of their portable record players, still not sure how they considered it portable considering the amp is probably over 10 lbs. and I think the speakers had 6" or 8" woofers

by **battradio** » Mon Sep 10, 2012 10:48 pm

If your avitar is what you wanted to post your fine , most portables don't have a power transformer .
http://www.edcorusa.com/p/795/cxse25-8-10k
http://www.edcorusa.com/p/511/gxse10-8-10k
Here is a couple of choices

I use photobucket to post photos

by **20to20** » Mon Sep 10, 2012 10:54 pm

Thinker1920 wrote:So I've tried to post a pic about 20 times with both IE and Firefox and I'm starting to go nuts

What's wrong with what I have? It has a good clear sound, just wanted to see if I could extend the range. and I like the S.E.T. amps and I haven't seen a lot of console pulls that are Single ended.

That amp probably has adequate transformers for the speakers that it has. Since it seems to have a 2-way speaker and uses 12ax7/6BQ5 it is probably rated for 6W per channel. Those SE trannies are probably rated 80hz - 16Khz but the speakers are likely only good for that too. Will you be attaching better speakers?

EDIT... I see we posted at the same time.

by **Thinker1920** » Mon Sep 10, 2012 11:03 pm

the cornwalls are rated down to 38hz I think?

by **Thinker1920** » Mon Sep 10, 2012 11:08 pm

so do you think it would be worth it to upgrade the output transformers? Or should I sell it and buy something else? (since the outputs are about $84 a pop :p ) what would be the affect to the overall sound if I changed them? And the avitar is the amp I'm talking about,

side thought if other portables didn't have power transformers how did they work? (???)

by **20to20** » Mon Sep 10, 2012 11:16 pm

Thinker1920 wrote:the cornwalls are rated down to 38hz I think?

Yep, I was referring to the originals that came with the portable.

So if you want to shell out the U.S. UncleSamoleans for some higher spec trannies, why not go for it? The new ones probably won't fit in the existing space though.

My thought is to keep it as is and build another based on the circuit, with the better OPTs, just for kicks. I have a little Magnavox SE that has the same tubes and similar OPTs and with good speakers it sounds fantastic. I wouldn't consider changing the OPTs at all...

by **Thinker1920** » Mon Sep 10, 2012 11:25 pm

it does sound pretty awesome as is just wondering if it would be worth the tweaks, with the cornwalls at 20% volume its plenty loud, and turned up to 50% it shakes you. Just wondering what I'm missing with the limited freq. Response. And the output smell a little funky when they warm up :))

I think its just there age maybe I should change them out with the cheaper ecor's?

by **20to20** » Mon Sep 10, 2012 11:26 pm

Thinker1920 wrote:so do you think it would be worth it to upgrade the output transformers? Or should I sell it and buy something else? (since the outputs are about $84 a pop :p ) what would be the affect to the overall sound if I changed them? And the avitar is the amp I'm talking about,

side thought if other portables didn't have power transformers how did they work?

Many cheap portables used different tubes with fliaments that used direct line voltage divided between them.

Your amp has the extra 12ax7 for the phono amp. What input connections are you using? Just phono?

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Changing output transfromer increase freq. response?

Changing output transfromer increase freq. response?

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