I bought my Harman Kardon HK6250 integrated amplifier used with the expectation of using it exclusively with my Energy C100 bookshelf speakers when it would be overkill to warm up my vintage McIntosh. It's done its job and more- I found that it pairs surprisingly well with my ATH-AD2000s. It has a clean sound but tends to sound thin (yet neutral) at times. Detail is better than the Meier Audio Headfive and dynamics are handled well. Vocals are more fluid and natural, the presentation fuller and warmer, and the soundstage deeper. Music comes alive on the HK6250.
It drives my Energy speakers with plenty of power to spare. In this configuration some graininess can come through esp. with female vocals, and it can sound a little unnatural at times. It's an excellent match for movies but can only dream of touching the McIntosh for music.
Strangely the HK6250 is a terrible match with the Sennheiser HD-595. The sound is muddy and bass heavy which is surprising as these characteristics aren't present in the slightest degree with other headphones.
With the Ultrasone HFI-680 the HK6250 has tighter bass than the Headfive but vocals are a little distant- not an issue with the ATH-AD2000. Otherwise the overall sound is fairly similar.
I should mention that I've modified my unit with Nichicon Muse capacitors and Dale RN resistors in the direct signal path. The modifications did little to the sound signature but seem to have slightly increased the sense of detail.
My ranking of this amplifier compared to others I own:
Audio-Technica ATH-AD2000: McIntosh 1500/HK6250/Meier HeadFive
Sennheiser HD-595: McIntosh 1500/Meier HeadFive/HK6250
Ultrasone HFI-680: McIntosh 1500/Meier HeadFive/HK6250
Energy C-100: McIntosh 1500/HK6250
The Harman Kardon 6250 has the capability to excel- but only if you choose your headphones or speakers wisely. If you're looking for an inexpensive amplifier for your ATH-AD2000s this model is a solid choice.
It drives my Energy speakers with plenty of power to spare. In this configuration some graininess can come through esp. with female vocals, and it can sound a little unnatural at times. It's an excellent match for movies but can only dream of touching the McIntosh for music.
Strangely the HK6250 is a terrible match with the Sennheiser HD-595. The sound is muddy and bass heavy which is surprising as these characteristics aren't present in the slightest degree with other headphones.
With the Ultrasone HFI-680 the HK6250 has tighter bass than the Headfive but vocals are a little distant- not an issue with the ATH-AD2000. Otherwise the overall sound is fairly similar.
I should mention that I've modified my unit with Nichicon Muse capacitors and Dale RN resistors in the direct signal path. The modifications did little to the sound signature but seem to have slightly increased the sense of detail.
My ranking of this amplifier compared to others I own:
Audio-Technica ATH-AD2000: McIntosh 1500/HK6250/Meier HeadFive
Sennheiser HD-595: McIntosh 1500/Meier HeadFive/HK6250
Ultrasone HFI-680: McIntosh 1500/Meier HeadFive/HK6250
Energy C-100: McIntosh 1500/HK6250
The Harman Kardon 6250 has the capability to excel- but only if you choose your headphones or speakers wisely. If you're looking for an inexpensive amplifier for your ATH-AD2000s this model is a solid choice.
