That's only because with tube amps you can actually hear the distortion when you turn it up too high. You can't tell when you're distorting a SS amp 'cause it all sounds distorted. :cool::rolleyes::oQuote:
Originally Posted by dbale
Printable View
That's only because with tube amps you can actually hear the distortion when you turn it up too high. You can't tell when you're distorting a SS amp 'cause it all sounds distorted. :cool::rolleyes::oQuote:
Originally Posted by dbale
Actually, tube amps have much higher distortion than SS amps. It's just a fact that some people prefer 'tinted' tube sound to 'clinical' SS sound.
It depends on how you quote your distortion figures. Nelson Pass rates distortion on his 25W amps at 1W into 8 Ohms at 1KHz FIRST WATT PRODUCTS I would hope distortion is low at such low levels.Quote:
Originally Posted by mah
My TS cathode follower is described by the designer as so: 3. Very linear, low distortion. The cathode follower is inherently a very low distortion configuration. Residual THD is less than 1% just before clipping. Distortion drops to just a few tenths of one percent at lower power levels.
Transcendent Sound Cathode Follower Tube Amp
That's a much more realistic way to represent an amplifier.
By the same token, Altecs never look good by the numbers, they just sound great.
1% is very high compared to SS amps. Of course only keen-eared audiophiles will get ear-bleed at 1% - most of us won't usually notice. :o
Again, the "less than 1% THD claimed was "just before clipping". It is only a few tenths at lower levels. Numbers are just numbers and without a unified standard of measurement, can be made to represent almost anything.Quote:
Originally Posted by mah
That said, it is possible that this minimal distortion actually adds to the musicality of a well designed tube amp rather than detract from it.
I would think speaker distortion would be more noticeable before amp distortion would even be on the radar.
alancohen
I find I can measure the coils mH on the winding rig . I clean the varnish off the coil start wire, and clip lead it to my meter.I clip a second test lead to a single edge razor blade and lightly nick the coil finish wire , making connection to the supply spool with out cutting the wire. Then if my coil measures low , just continue winding , if its high , unwind a few turns returning the extra length to the supply spool . The 1/4 20 screw and nut should be brass or al, not iron.
Also do not be afraid to splice on more wire. I like to solder the splice and cover the splice with a wire nut.
If the hand drill is a 5:1 gear ratio it makes the counting easier.
Mounting coils: I use two cable ties to hold the coil together and 4 more to hold them flat .If they are mounted standing up, I use 3 ties.
On your layout, I suggest the coils be re oriented to be at right angles.
Don
[QUOTE=alancohen;1849693]OK then...all inductors are done. The 4.7s weight over 2#! This one actually measures 4.7, but the scale seems to have an affect. They are .68 Ohms, exactly what the Shavano website said they should be.
alancohen
If you want to lower the DCR on the 4.7 mH try this trick. Start with two supply spools and wind two two #15 AWG wires in parallel (bifilar winding) . This reduces the DCR by 1/2 to .34 Ohms. Of course, we put in twice the copper. The calculations now are made for 12 AWG . When you double or half the cu, the gauge changes by 3 . Remember to connect the start wires together and the finish wires too.
Don
According to these peoples claims the lower the DCR the better?
North Creek Music Coil Inductors
After the first one that was so far off I guestimated the length required pretty well. On the next four I was only .03-.05 mH high and only had to cut off a few turns to dial it in. The last one I didn't have enough wire to get it all in one piece so I soldered another length on and kept wiring.Quote:
Originally Posted by donaldpatten
I had the brass rod and nylon nuts and washers, but I was getting pretty close without having to measure on the spool. If I were going to make a lot of these I would choose not to waste even 2' of wire since it is not cheap. I think I ended up with about 20' of wire in the trash after 6 coils. Not too bad. I also have very little left over so doubling up is not in my future either. I think I can live with the .68 Ohms, especially since I'll be going into 16 Ohm speakers which will half the effect of the DCR in the crossover compared to 8 Ohms.
I also saw this cool layout on Audiogon.
http://www.hostboard.com/forums/hbmc...2013/05/25.jpg
He builds and sells a 500Hz crossover for $599 (search Altec and you'll see them). I like the 2-tier set up. It would allow separating the coils even more. I could have the big 4.7 in the middle and the other two standing up on each end. This would also permit me to secure them flat against the endplates, yet still upright. I like it.
Query: I see he used 14ga lamp cord for the wiring. Is there any point to this, considering the leads from the caps and resistors are probably only 20ga at best? I would think the "weakest link in the chain" principle comes into effect here. On my A6s I think there is 20ga hookup wire throughout the n1285 and running to the drivers.