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Do I need to upgrade my output transformers?

mchrismag

Member
2015-02-25 11:52 pm
Hey, guys. Some advice/opinions needed here. I am currently running some edcor gxse 15-8-5 output transformers. All of the speakers I currently own are small monitor speakers. Right now I have small Fostex fe103en speakers running with my sse and for low volume and late night listening I really like them. After a few months break in I decided to crank 'em up a bit and see what they can do. I heard some distortion in the bass at higher levels and thought maybe it's the speakers. I had my amp wired in triode with no feedback. Didn't think I needed it with my speakers limited bass response. Well, I decided to try cathode feedback with them just to see what would happen. No more distortion in the bass. When I push the amp too hard it just starts to compress the sound but no fuzz type distortion in the bass. I noticed the same thing with my rca speakers which have more bass but still have small woofers (5") I plan on building some larger speakers, probably one of the pi speakers which have much larger woofers and deeper bass response. I could just wire my amp with cathode feedback but here's the problem...I think it sounds better without any feedback except for the fuzzy bass at higher volume. I can't quite describe what I am hearing but it just sounds better to me. I'd like to run it in triode with no feedback with the new speakers but I am thinking the bass will sound distorted this way. So after a long winded explanation (sorry) would I be better off getting some better transfomers before I build the speakers? Or maybe an output tube change would help? Or maybe the pi speakers would sound better with feedback no matter what transformers I have?
 
Well, maybe specify how high you cranked them up - SPL meter or smart phone app should be close enough for this purpose. Depending on the speaker enclosure design, you can't except much in the way of LF extension from the FE103s at anything above 90dB and below, maybe 80HZ

I doubt upgrading the OPT or any component further upstream than the amp won't eliminate the driver's limitations.
 
I still have a pair of GXSE15's on my SSE with KT88s and it sees regular service with a pair of Super Pensils. No bass distortion that I've ever noticed (and I do occasionally crank it).

I have a pair of FE103s as well and I haven't noticed any distortion in the bass, but I also don't crank those much (they're in a small room). I think any distortion you hear is more likely related to the little Fostexs than your output transformers.
 

mchrismag

Member
2015-02-25 11:52 pm
Just a little update to this thread. I am going to leave my output transformers alone. I really like the midrange with the sse and the fe103en. I have 4 dynaudio 17w75s currently just sitting around. My Dad is going to give me his Bryston 3b. So I am going to try using the sse on the fostex for mids and treble and the 3b on the dynaudios for the bass. I'm going to buy an inexpensive active crossover to experiment with this combination and then maybe get a better one later if I really like it.
 
I'm a noob. And I have been lurking reading the threads.
I just ordered my SSE board.
I am planning on using the same tubes, EL34s, and transformer choices as mchrismag- Allied pt and Edcor GXSE opts.
I have a new set of Klipsch r26f (97dB) speakers I will be using.
I just wanting to make sure I won't be short on power for good bass, or should I get the Edcor CXSEs?



(All other parts on build list are appropriate?)