Tube Amp Recommendations, please

[SteveFord]

I can't stand the headphone jack on my Jolida JD100 no mo'.
I'm considering either a Woo Audio 3 Plus or 6 for my AKG701 and Beyerdynamic 880s.
Is there any reason why I shouldn't go with these or perhaps be looking at something else?
My systems are pretty good and I know that just plugging the headphone into the CD player is holding things back.
Price range for headphone amp, under $800 new.
Thanks in advance,
Steve Ford
P.S.
Love the old Stax Sigmas on the downstairs system!
Great site, by the way.

 

[glitch39]

For the 701 and 880, I would recommend the flexibility of the Woo6. Roll the tubes and still be under budget

 

[apatN]

Or the balanced Little Dot MKVI: Welcome to Audiophilechina

 

[jpstereo]

Mapletree Audio Ear+ HD.

 

[audiowize]

Quote:

Originally Posted by SteveFord /img/forum/go_quote.gif I'm considering either a Woo Audio 3 Plus or 6 for my AKG701 and Beyerdynamic 880s. Is there any reason why I shouldn't go with these or perhaps be looking at something else?

Yes, absolutely. You will get pretty poor results out of an OTL amp with the 701's. (880's will be ok). The low impedance and low sensitivity of the 701's means you get pretty poor performance out of an OTL circuit. In an OTL amplifier, power output goes down as impedance goes down. The 701's are both low impedance and low sensitivity. (I know this problem personally, as I have 701's and 2 OTL amps).

The Woo 6 is a better choice, as the transformer coupled output will be a better match to low impedance headphones. Unfortunately, the maximum possible voltage gain with the tube they are using will really limit the capabilities of this amplifier (they mention it is like 1/2 a 6SN7 and a 2A3, which would mean in a perfect world you would want 3 volts of input signal for full output, in their app, it might be more like 5). If you are using a source with significant output voltage, this might not be an issue. Also, it is really obvious that the Woo is AC heated, which may also present problems.

Unfortunately, Woo doesn't list output power into a given impedance, so it is tough to know. You might also look into building your own, like a Bottlehead SEX amp or one of the transformer coupled projects in the Headwize library.

 

[SteveFord]

Thanks for your help, you guys have given me something to think about and some good questions to ask the manufacturers as well.
If I have to use the 880s, well, worse things could happen!

 

[Skylab]

Your 880's will sound awesome on an OTL tube amp, but as posted above, you need a transformer-coupled amp like the WA6 for the K701's. Another option is the ASL MG Head III, which can operate either transformer-coupled OR OTL.

 

[Frihed89]

I have never owned a Woo, or even heard one, but I do own the MAD Ear + HD and I love it. It is transformer coupled. It drives my 701s very well. Doc will put high and low gain plugs in it if you want. In addition, MAD is one of the best firms of any kind i have ever dealt with when it comes to customer service.

 

[cswann1]

Is 105db really considered low sensitivity?

 

[Skylab]

It is the low impedance of the K701 that could pose a problem for an OTL amp, not the sensitivity.