Tube Amps / Music Electronics
For current discussions, please visit Music Electronics Forum. New: view Recent Searches.
New: visit Schematic Hell!
The sunn still shines online!

Listen to great tunes streaming live right now!

ampage archive

Vintage threads from the first ten years

Search for:  Mode:  

So Flo Smart Aleck

1/29/2000 2:41 PM
So Flo Smart Aleck
Anyone heard or played this amp or any other of his amps? How about feedback. Thanks.
2/6/2000 5:38 AM
What's the single ended deal, anyway?
I've been wondering myself about this amp. Hasn't anyone heard or played on it? What are the disadvantages of single ended amps besides the low power (compared to push-pull with the same tubes) and the expensive tranny? These two things are not that big a deal when we're looking for tone, so I figure there must be more. Enlighten us, please.  
2/6/2000 7:06 PM
Ken Gilbert

No, those are pretty much all the disadvantages to SE operation... larger, more expensive tranny, which is harder to make in high power versions. Not saying it can't be done, just that it's harder.  
There's also no inherent cancellation of even harmonic distortion generated in the output stage when you're using SE. With PP, the EHD is nullified in the OPT. Not really a concern with MI stuff.  
2/11/2000 3:21 AM
Jimmy Page
Single ended amps have restricted dynamic range and tend to accentuate even harmonics making them warmer sounding. They won't slam your balls to the wall like PP but rather give a more intimate sound with a considerably smaller sound stage. SE amps are not better or worse than PP amps. Rather it's a question of what tool to use for a specific job. No amplifier will do it all. SE's just give you another choice in constructing your own unique sound.  
Your pal,  
2/11/2000 6:12 PM

Jimmy and Ken, thanks for the replies. I did know that the SE amps are a lower wattage thing. Ken, can you tell me where costs start becoming prohibitive? Can you get to 15-20 watts before it gets rediculous? You lost me with the "MI" reference. Jimmy, when you say they don't have as much dynamic range, I'm assuming that a well designed PP amp will have more than an equally powered SE amp. Is that correct? I would like to start an SE project soon. I'm hoping for it to get close to 20 watts. Thanks again.  
2/11/2000 7:43 PM

I'm not sure about this reduced dynamic range notion attached to SE designs. Probably the fault of the old Fender Champs, which have some of the dinkiest output iron on the planet. PP and class AB biasing are supposed to reduce sensitivity, at least according to the Radiotron Designer's Handbook.  
You say you want/need 20 watts? I think you can get 15 watts or so with a 6550, maybe more with a real KT-88 (that is, not Sovtek) or a KT-90. The other option is to parallel output tubes in SE. Check out the Super 6V6 project at for an example of this.  
The other thing to consider is whether you really need the watts. I'd suggest an efficient speaker to get the most out of the power. You don't need an EV or modern Celestion to take the power, so a speaker with a lower wattage rating, which will generally be more efficient, will give good results in this application. In GP's alnico speaker shootout, the Celestion Blue, with one of the lowest wattage ratings, was found to be the loudest speaker. All the hifi folks using SE 300B's use incredibly efficent speakers so about 9 watts (?) a side is plenty to fill the room. Most of us have no notion of how much power we really need because most speakers act like wet towels for our sound.  
2/11/2000 10:12 PM
Sideways Jaye

I thought sensitivity expressed in db's was the measure of efficiency. Am I wrong? It makes sense that a "lighter weight" speaker would need less oomph to get it pumping, but in fact, a lot of high power speakers have higher sensitivity ratings, and I've used high wattage speakers to make my low powered Fenders (although not SE) louder as well as cleaner. Is my thinking here all off?
   Page 1 of 3 Next> Last Page>>