I have 125. Grados are an acquired taste, that's for sure. But good for classic rock, etc. but definitely always sound closed. Switching from Grados to something like AKG 701 is a really eye opening experience. Headphones vary so much in sound compared to most hi-fi speakers. It's so subjective.
Salas:
What's your recommendation for power amps 40-100W? Prefer Class A or deep A/B. Also prefer a lot of current for 89db 3-ways with a 3.2R min.
I am contemplating upgrading my dual output pair F5 to from 24 to 32V rails (50W/8R) or I could just try a different design. i like the F5 topology but I am open to suggestion.
What's your recommendation for power amps 40-100W? Prefer Class A or deep A/B. Also prefer a lot of current for 89db 3-ways with a 3.2R min.
I am contemplating upgrading my dual output pair F5 to from 24 to 32V rails (50W/8R) or I could just try a different design. i like the F5 topology but I am open to suggestion.
The issue was oscilation on the output stage of the power amp.
Now it works perfectly with the DCG3 as well as with the other preamps.
You are entering expensive territory if to retain the first watt pure. Why not try passive biamping with an economic class D hooked at the woofers and keep the F5 on mids & highs first I would say. Level the voltage gains of course.
Congrats. I have noticed some blue little caps on the OPT stage of your proto amp's photo, that is why I talked look in compensation right away. DCG3 drives much more vigorously the interconnects capacitance so it passes signal bandwidth easier than the DCB1...
Now you must probably have better "locking" sonics too from the combo.
F5TV3 is really very good but you must build them monos. Also using Toshiba Mosfets (which I see you have) instead of IRF or Fairchilds puts them in another class. Great thing about these is that you can adjust harmonics to taste.
Why not convert what you have now into a balanced amp and build another balanced for the other channel? Will take care of your power needs.
nash
Stable at any length. The only special advice I could give is in the rare occasion you want over 6 meters cable length to headphones (in a recording studio?) it could be better to damp the cans output with 10R at RZ resistor's place, instead of ~0R native impedance output with just jumpers, so to avoid ultrasonic response peaking tendencies from adding much cable capacitance to that inductive transducer's load. Unless its a planar. On the other hand the line output is already damped with 50R conforming to the laboratory standard. Nothing to do there even for very long cables.
This is also what i did conclude some years back, when my son and i was taking an evening / night listning to F5 vs. AlephJ... Back then i had the normal build F5/AlephJ's pcb, and the mounting holes was allready in place on my chassis, so swapping them in/out was a matter of less than 30minutes
... Guess i wrote this before, but son actually with young ears liked the AlephJ most (Especially topend) he liked a bit "rounder" tone he said! -Well i kindoff followed him eventhrough i couldnot hear as much as he could!I like to read everyday, that builders here like the DCG3 pre.
Jesper.
In post #1394 Vgeorge shows a biamped four way horn system including a dbx processor for active bass. Its connected with two six meters cable runs in parallel from line output. That's equivalent to twelve meters for parasitic cable capacitance. About 8K combined load in his case. So no worries.
Its still good to use low capacitance cable like 50-60pF per meter if you can so to keep its filtering mild for less phase shift and less driving power absorption in the cable interface.
Unfortunately, I have no balanced sources. I mostly listen to vinyl.
I might just get a 25V transformer (33V rails) and try that. It's a tradeoff, rail voltage vs. bias due to the heat involved. Higher voltage rails will give me more wattage but a smaller class A envelope due to having to reduce the bias. Not sure what will work better and unfortunately the transformer is an expensive part.
But i guess you can never have too many transformers lying around.
last night using a meter I measured the AC output when playing about as loud as I want. It was 6-7V. So, I am clipping or close to it on peaks with only 25W.
But the Salas DCG3 sounds excellent, that's for sure.
I may let a friend borrow it who is using a Pass B1 with some big Emotiva amps now. he will probably like it. He liked the BA-3 front end as well. All of them were way better than the Cambridge Audio thing he was using before.
For your speakers sensitivity and impedance, a 120W at 8 Ohm nominal amp would be good. Mine has 40W on my rails (22-0-22 Tx) but for 5dB more sensitive speakers than yours. Although comparable in impedance. That allows my amp to behave alike 100W+ on your speakers. There are 100-200W amp projects in the forum as well as current feedback SMT boards from Lazy or Sonny. It can easily take about 1k$ to fully finish any SOTA DIY stereo amp at this power range IMO.
I believe that biamping, the woofers with a cheap ebay style 200W Class D and keeping the F5 for the rest, can be an easy experiment on the other hand.
I believe that biamping, the woofers with a cheap ebay style 200W Class D and keeping the F5 for the rest, can be an easy experiment on the other hand.
If he doesn't prefer the DCG3 over the Pass B1, then there is either something wrong with his system or his hearing.
Of course the B1 is a buffer with no gain where the DCG3 will have some gain.
And...as we all know, "louder" is usually perceived as sounding "better".
Maybe not a fair comparison.
The B1 may be a simple and easy-to-build buffer, but I personally think it totally blows in the SQ department.
The BA-3 sounds better than the B1, but can have too much gain for most sources.