Other than a certain someone who believes the Bada PH-12 is the be-all end-all of all headphone amps, there's very little information around on the PH-12. Well, a few weeks ago I was auditioning tubes & CD players with some guys at a friend of a friend's place when I noticed he had a PH-12 sitting in a corner, and near the end of the listening session I asked if it would be ok for me to come back and take a listen to it some other time. He said sure, provided I bring along my own tube amp so he could also see how it measured up. So this past weeked we did an extended listening session of his PH-12 against my Objective-Interim 6SN7 amp, and to keep things fair I brought along a box of tubes. Also had a friend along to keep me honest and contribute her modded Senn 650's.
Gear used: Classé CDP-102 CD player, modded Denon 650F CDP, modded Senn 650, Grado RS-1 (so nice to hear one again), modded AKG K340, various DIY interconnects
Most of my listening was done using my K340 and the RS-1. The Denon was used with the K340 and the Classé with the RS-1, it matched better that way.
The good news, the amp is very quiet, there's some barely audible background hiss with the RS-1 and no noise at all with the other headphones. Frequency extension is good on both ends with no peaks, dips, or other funny stuff. It is pretty neutral, no solidstate harshness in the treble & midrange, no out of control bass. There's nothing that sticks out and offends me, in other words, no real errors of commission. So far, so good.
(Note, the next paragraphs are going to sound pretty negative. It's not because the amp sucks, it doesn't, it's because I'm spoiled by my Objective-Interim Amp and as a result I have rather high standards.)
But it's not perfect, what bugged me the most was the lack of low-level detail & resolution. This is not the ability to make some sound in the background pop out so you can hear it clearly, but the ability to distinguish between subtly different sounds that are barely above the audible limit. To use an example, telling the difference the sound of a singer quickly moistening her lips and the sounds of a singer pulling her moistened lips apart just before she begins to sing. On highly resolving gear, those 2 sounds will be noticeably different, on gear that's not up to that level, it all sounds the same.
The Bada PH-12 falls into the latter group in that it homogenizes low-level details. On tracks 2,8 & 9 of "Little Earthquakes" by Tori Amos, there are a fair number of the subtle vocal cues which I mentioned above. Sometimes she sings with a wet throat, sometimes she licks her lips, there's times when she pulls her stuck lips open and if you listen real hard you can hear her pull her tongue off the back of her front teeth. These are very hard details for a system to get right, especially at my normal listening level of about 60dB. The Bada fails at this. I can clearly hear Tori pulling her lips apart, but that's all I ever hear her doing, the subtle distinguishing cues are lost.
This problem carries over to other instruments as well, but was most noticeable on cymbals, to be specific, the live unamplified ones on the "Trinity Sessions" album by the Cowboy Junkies. Almost every cymbal hit should be subtly different, the cymbals are never in the exact same position when struck, sometimes they're tilted one way, sometimes the other, sometimes it's going up, sometimes it's going down. All this will have affect the tone & final sound of each cymbal hit and how the sound spreads into space, and on good gear it comes through.
With the PH-12, some of those small details are lost. The effect is barely noticeable with the louder cymbals at about the 3 minute mark of "Sweet Jane" where Margo is singing "la-la-la-lah la-la-lah", but during the instrumental part of "Dreaming my dreams with you" the cymbal hits start sounding far too similar. Every single one is unique on my amp, with the Bada, it sounds like there's only 4 or 5 different cymbal tones which get looped over & over again for a whole minute.
Other issues I had were a slight lack of speed and note & instrument separation, the last 2 being I believe a result of the speed (lack thereof) and loss of low-level details. The Bada is a decently fast amp, but not up to the level of say, a Dynahi or my own amp. It fails to keep the basslines going in "Wham" by SRV or "The Lemon Song" by Led Zeppelin. Notes do blend in the faster passages when the basslines are down a bit in level, and when John Paul Jones cuts loose on "The Lemon Song" the bassline always seems to be falling half a beat behind.
Back to more positive stuff. The amp will have pretty good tone, provided the right tubes are used. In my case this means either the RCA or National Union VT-231 in the main gain position and 2 GE Canada 6SN7GTA's. This gives a rich midrange sound with good drive & rhythm at the expense of a tiny bit of low level detail. Using the Sylvania VT-231 instead of the GE's gives a tiny bit more detail but then I don't get enough bass and the PRaT goes out the window.
Other tube combos were not so good. Going the other way round with the GE's & RCA's cost a bit more detail and the tone wasn't as good. Frequency range is better though. Using the 6N8P and 2 Electro-Harmonix gold pin 6SN7 as championed by drarthurwells resulted in a sound which I hated. Dry midrange, harsh treble, tight but slightly bumped up bass. This also resulted in a large loss of soundstaging and low-level details. Using all RCA VT-231's made it too syrupy sweet and rolled off the treble too much, which made it a complete disaster with the HD650 & K340. With the RS-1 the bass got too bloated and the midrange was just too much. Might be fine with an HP-1000 but I wouldn't bet on it.
Soundstaging & imaging were surprisingly good. The soundstage is not quite as big as the one on my amp, but it comes pretty close. The main difference is it doesn't quite wrap around the back of my head the way mine does. Imaging is precise but there's a bit of unnaturalness in how the sound radiates outward from the vitual source, especially noticeable on cymbals & piano. Instead of the sound going outwards in all directions and then reveberating off the various boundaries, it tends to beam towards me in a cone. Instead of a sphere of sound, it's a cone of sound. But that's nitpicking since I can count the gear that does it right on one hand.
The quick summary is the PH-12 is a good $450 amp, but it comes nowhere close to extracting the ultimate potential of the good NOS 6SN7 tubes. It will respond to tube rolls, and will improve with better tubes, but IMO, it hits the point of diminishing returns pretty hard when going to anything better than the GE Canada 6SN7GTA or the RCA side-getter 6SN7GTA's. The full performance of the good tubes such as the RCA, Sylvania, and National Union VT-231's are left in the tube so to speak.
It's a good $450 amp and I'd recommend it, but it's not the be-all end-all amp. Singlepower SLAM's, my Objective-Interim Amp, and Biggie's modded tube amp can all extract a lot more low-level details. Of course they all cost a lot more, just getting the power supply parts alone for my amp will get you 3/4 of the way to the PH-12, nevermind the output transformers & other parts, and I don't even want to guess what Biggie's amp costs. For $450, it's a solid performer.
Gear used: Classé CDP-102 CD player, modded Denon 650F CDP, modded Senn 650, Grado RS-1 (so nice to hear one again), modded AKG K340, various DIY interconnects
Most of my listening was done using my K340 and the RS-1. The Denon was used with the K340 and the Classé with the RS-1, it matched better that way.
The good news, the amp is very quiet, there's some barely audible background hiss with the RS-1 and no noise at all with the other headphones. Frequency extension is good on both ends with no peaks, dips, or other funny stuff. It is pretty neutral, no solidstate harshness in the treble & midrange, no out of control bass. There's nothing that sticks out and offends me, in other words, no real errors of commission. So far, so good.
(Note, the next paragraphs are going to sound pretty negative. It's not because the amp sucks, it doesn't, it's because I'm spoiled by my Objective-Interim Amp and as a result I have rather high standards.)
But it's not perfect, what bugged me the most was the lack of low-level detail & resolution. This is not the ability to make some sound in the background pop out so you can hear it clearly, but the ability to distinguish between subtly different sounds that are barely above the audible limit. To use an example, telling the difference the sound of a singer quickly moistening her lips and the sounds of a singer pulling her moistened lips apart just before she begins to sing. On highly resolving gear, those 2 sounds will be noticeably different, on gear that's not up to that level, it all sounds the same.
The Bada PH-12 falls into the latter group in that it homogenizes low-level details. On tracks 2,8 & 9 of "Little Earthquakes" by Tori Amos, there are a fair number of the subtle vocal cues which I mentioned above. Sometimes she sings with a wet throat, sometimes she licks her lips, there's times when she pulls her stuck lips open and if you listen real hard you can hear her pull her tongue off the back of her front teeth. These are very hard details for a system to get right, especially at my normal listening level of about 60dB. The Bada fails at this. I can clearly hear Tori pulling her lips apart, but that's all I ever hear her doing, the subtle distinguishing cues are lost.
This problem carries over to other instruments as well, but was most noticeable on cymbals, to be specific, the live unamplified ones on the "Trinity Sessions" album by the Cowboy Junkies. Almost every cymbal hit should be subtly different, the cymbals are never in the exact same position when struck, sometimes they're tilted one way, sometimes the other, sometimes it's going up, sometimes it's going down. All this will have affect the tone & final sound of each cymbal hit and how the sound spreads into space, and on good gear it comes through.
With the PH-12, some of those small details are lost. The effect is barely noticeable with the louder cymbals at about the 3 minute mark of "Sweet Jane" where Margo is singing "la-la-la-lah la-la-lah", but during the instrumental part of "Dreaming my dreams with you" the cymbal hits start sounding far too similar. Every single one is unique on my amp, with the Bada, it sounds like there's only 4 or 5 different cymbal tones which get looped over & over again for a whole minute.
Other issues I had were a slight lack of speed and note & instrument separation, the last 2 being I believe a result of the speed (lack thereof) and loss of low-level details. The Bada is a decently fast amp, but not up to the level of say, a Dynahi or my own amp. It fails to keep the basslines going in "Wham" by SRV or "The Lemon Song" by Led Zeppelin. Notes do blend in the faster passages when the basslines are down a bit in level, and when John Paul Jones cuts loose on "The Lemon Song" the bassline always seems to be falling half a beat behind.
Back to more positive stuff. The amp will have pretty good tone, provided the right tubes are used. In my case this means either the RCA or National Union VT-231 in the main gain position and 2 GE Canada 6SN7GTA's. This gives a rich midrange sound with good drive & rhythm at the expense of a tiny bit of low level detail. Using the Sylvania VT-231 instead of the GE's gives a tiny bit more detail but then I don't get enough bass and the PRaT goes out the window.
Other tube combos were not so good. Going the other way round with the GE's & RCA's cost a bit more detail and the tone wasn't as good. Frequency range is better though. Using the 6N8P and 2 Electro-Harmonix gold pin 6SN7 as championed by drarthurwells resulted in a sound which I hated. Dry midrange, harsh treble, tight but slightly bumped up bass. This also resulted in a large loss of soundstaging and low-level details. Using all RCA VT-231's made it too syrupy sweet and rolled off the treble too much, which made it a complete disaster with the HD650 & K340. With the RS-1 the bass got too bloated and the midrange was just too much. Might be fine with an HP-1000 but I wouldn't bet on it.
Soundstaging & imaging were surprisingly good. The soundstage is not quite as big as the one on my amp, but it comes pretty close. The main difference is it doesn't quite wrap around the back of my head the way mine does. Imaging is precise but there's a bit of unnaturalness in how the sound radiates outward from the vitual source, especially noticeable on cymbals & piano. Instead of the sound going outwards in all directions and then reveberating off the various boundaries, it tends to beam towards me in a cone. Instead of a sphere of sound, it's a cone of sound. But that's nitpicking since I can count the gear that does it right on one hand.
The quick summary is the PH-12 is a good $450 amp, but it comes nowhere close to extracting the ultimate potential of the good NOS 6SN7 tubes. It will respond to tube rolls, and will improve with better tubes, but IMO, it hits the point of diminishing returns pretty hard when going to anything better than the GE Canada 6SN7GTA or the RCA side-getter 6SN7GTA's. The full performance of the good tubes such as the RCA, Sylvania, and National Union VT-231's are left in the tube so to speak.
It's a good $450 amp and I'd recommend it, but it's not the be-all end-all amp. Singlepower SLAM's, my Objective-Interim Amp, and Biggie's modded tube amp can all extract a lot more low-level details. Of course they all cost a lot more, just getting the power supply parts alone for my amp will get you 3/4 of the way to the PH-12, nevermind the output transformers & other parts, and I don't even want to guess what Biggie's amp costs. For $450, it's a solid performer.
to sound good will not end up a budget amp.
