Hi Louis,
I think i have the same clone amp A1 and i did have the ST MC33078 delivered with the amp from China on them, but i do not think they are original, so i buy the real MC33078 to see if they are, they are cheap from a supplier here in Germany, about 1,4€.
And i buy the LM4562, they are also cheap, about 2€, so i will see if there is a change in sound between de China MC33078 and the ones i do buy from Germany, and the LM4562 i wil also test in the A1, i hope it will work, i did read that they are oscillating in manny amps, so i hope it wil work, so i can test the sound.
Hi All,
For all Opamp rollers that still have their A1 (clones) hanging around I would like to share some experiences that might be of interest to you.
Recently I replaced the current Muses8820 opamps with Sparkos ss3206 in my HD-8-A1-Pro headphone amplifier.
I did several listening tests and would like to share my findings with A1 (clone) owners and other readers.
As a reference (and for those interested) I have included the Custom Headphone Target Curve that I used to EQ my HiFiman HE6se v2 headphone for the listening tests.
My audio-chain consisted of:
Default opamps of the A1 (and clones) are the ST MC33078 which do the job but lack finesse and can sound harsh and holow with ill-defined lows.
In the past years, after numerous tests, I settled on the Muses8820 which improved the performance of the A1 significantly with a warm inviting sound, improved dynamics and more detail.
Muses 02 performed also very well but where a little to bright in combination with my (custom) Beyerdynamics T90 so I settled on the Muses8820.
When I swapped the above with the Sparkos ss3602 this gave me another significant additional improvement in aspects like level of detail, dynamics and soundstage.
To my surprise the A1 amplifier was even capable of driving my HiFiman HE6se v2 which is quite an accomplishment.
The sound was warm, smooth, natural and detailed. I found myself rediscovering my music library as this upgrade really revitalised the HD-8-A1-Pro amplifier.
Sub-bass
In ‘Angel’ by Massive Attack the low frequencies are delivered with confidence without dominating or overshadowing the other instruments and fine details.
Bass
In ‘Reconnaissance’ by Mitch Murder the A1/ss3602 combination proves it can kick some serious a.. in the bass department.
Mids
Vocals sound very naturally, ‘Layla’ by Clapton on Lockdown sessions (Live) sounds incredibly real and also the accoustic instruments on that recording are smooth and a real joy to listen to.
The guitar play on ‘Exploring the Blue’ by Lucas Bloom is very direct, dynamic and convincing but never harsh. His voice is natural and remains controlled also when the volume rises.
Dynamics are also on a very high level as could be heard at the end of Angus & Julia Stone’s ‘Draw Your swords’.
Highs
The upper frequencies are extended and delivered in a very subtle and sparkling way.
On some systems Chris Isaak’s ‘Blue Hotel’ for example can sound overly sharp but this was absolutely not the case with the ss3602s.
Conclusion:
Overall I was very positively surprised that there still was so much potential in the little dated design of the A1 amlifier.
With the ss3602 I was presented an immersive smooth, forgiving and addicting sound with well separated instruments and a wide realistic soundstage.
As mentioned it had no problem whatsoever driving my HiFiman HE6se v2 Headphones which have a reputation of being notoriusly difficult to drive.
For all Opamp rollers that still have their A1 (clones) hanging around I would like to share some experiences that might be of interest to you.
Recently I replaced the current Muses8820 opamps with Sparkos ss3206 in my HD-8-A1-Pro headphone amplifier.
I did several listening tests and would like to share my findings with A1 (clone) owners and other readers.
As a reference (and for those interested) I have included the Custom Headphone Target Curve that I used to EQ my HiFiman HE6se v2 headphone for the listening tests.
My audio-chain consisted of:
- Qobuz (Hi-res streaming service)
- Roon (running on Synology NAS)
- HQPlayer (running on Intel Nuc12i5) for upsampling and EQ
- Fibre optic Media Converters
- Gustard R26 R-2R DAC using it's internal (LAN) Network Audio Adapter
- VandenHull Integration Hybrid (single ended) RCA interconnect
- HD-8-A1-Pro headphone amplifier
- HiFiman HE6se v2 with custom cable by CustomCansUK
Default opamps of the A1 (and clones) are the ST MC33078 which do the job but lack finesse and can sound harsh and holow with ill-defined lows.
In the past years, after numerous tests, I settled on the Muses8820 which improved the performance of the A1 significantly with a warm inviting sound, improved dynamics and more detail.
Muses 02 performed also very well but where a little to bright in combination with my (custom) Beyerdynamics T90 so I settled on the Muses8820.
When I swapped the above with the Sparkos ss3602 this gave me another significant additional improvement in aspects like level of detail, dynamics and soundstage.
To my surprise the A1 amplifier was even capable of driving my HiFiman HE6se v2 which is quite an accomplishment.
The sound was warm, smooth, natural and detailed. I found myself rediscovering my music library as this upgrade really revitalised the HD-8-A1-Pro amplifier.
Sub-bass
In ‘Angel’ by Massive Attack the low frequencies are delivered with confidence without dominating or overshadowing the other instruments and fine details.
Bass
In ‘Reconnaissance’ by Mitch Murder the A1/ss3602 combination proves it can kick some serious a.. in the bass department.
Mids
Vocals sound very naturally, ‘Layla’ by Clapton on Lockdown sessions (Live) sounds incredibly real and also the accoustic instruments on that recording are smooth and a real joy to listen to.
The guitar play on ‘Exploring the Blue’ by Lucas Bloom is very direct, dynamic and convincing but never harsh. His voice is natural and remains controlled also when the volume rises.
Dynamics are also on a very high level as could be heard at the end of Angus & Julia Stone’s ‘Draw Your swords’.
Highs
The upper frequencies are extended and delivered in a very subtle and sparkling way.
On some systems Chris Isaak’s ‘Blue Hotel’ for example can sound overly sharp but this was absolutely not the case with the ss3602s.
Conclusion:
Overall I was very positively surprised that there still was so much potential in the little dated design of the A1 amlifier.
With the ss3602 I was presented an immersive smooth, forgiving and addicting sound with well separated instruments and a wide realistic soundstage.
As mentioned it had no problem whatsoever driving my HiFiman HE6se v2 Headphones which have a reputation of being notoriusly difficult to drive.
