Amp15 vs Amp4

[wadoka]

I decided to do a little back to back, just for fun. Both in the same system, same albums. The speakers are home made standmount 2 way with decent Seas drive units and aperiodic vents so they can be right up against a wall without boom.
CD player an ancient Philips cd160 with CDM2 transport running into a tda1353 NOS DAC. So not a high end system, but I like to think better than average ;)
Both amps using Panasonic FC input caps and running from torroids.

The first thing of note is that they both push my speakers louder than they need to go, so no obvious advantage to the Amp15 having three or four times the power.
The differences are really very subtle, I'd say the 15 has it by a nose but the 4 is 95% there. The overall character of the amps are the same, smooth light and fast. The 15 has an uncanny top end, a degree of detail and sparkle that is quite amazing, while the 4 merely very very good :)
They have pretty much the same 'amount' of bass, perhaps the 4 a little more being plumper, with the 15 slightly faster.
The midrange is a little smoother with the 4, the 15 is a little more precise.
The 15 does the trick of bringing 'live' recordings into the room better than the 4, the soundstage is larger with more subtle details.

Both are extremely good as we all know, the differences in character very minor.
The 15 has the edge in ultimate resolution, the 4 a larger edge on price.
I'd be happy with either, and am in fact happy with both! :D

[krilli]

Arrgh, I have a bad case of envy ...

[audiophool]

Nice write-up Wadoka[8D], Thanks.

[V-bro]

Great little test there Wadoka![8D]

It exactly confirms my experiences with them, making the AMP4 an incredible value for money amp. But -and I hope I'm not making Audiophool angry saying this-;) it is much harder to build for most diyers.

Again most have an issue with SOT-23 packages...[B)]

------X-max. can be several meters on any driver, too bad it can be done only once...------

[wadoka]

Thanks guys :)

I'll be doing other head to heads in the same system, perhaps an amp6b and an amp32-ps both up against the amp15, so I have a point of reference.

Of course, if someone wants to give me a Truepath I'll include that in the test too :) hehehe!

[wadoka]

Next up...Amp6b, but running from a laptop type 12v smps for comparison next.

The midrange is perhaps the most surprising area, vocals sound very nice indeed, full of detail yet smooth...the mid just sound 'right' to me.
Top end a little splashy, not as bad as most class a/b amps I've owned, not as crisp as other 41hz amps however. Bottom end a little soft by 41hz standards, lacking both weight and speed. Soundstage a bit flat and runs out of power pretty quickly...
...if this all sounds very negative, keep in mind I've owned Naim and Meridian amps that dont sound as good as the amp6b. But I've decided to compare to an amp15, so I have to call it how I think it sounds.

I suspect a better psu would help firm the bottom end a bit and better system matching, ie 4ohm highish sensitivity speakers would make a large difference to both perceived power and bass quality, as I was using 8ohm speakers of questionable efficiency. Top end improvement may also come from a better psu.

I am building some open baffles which are 12" drive units and measure 3.3ohm, these may be a better bet for the amp6b but unfortunately the amp6b I used to test is no longer here, having been sent back to its owner.

I suspect that the amp6 (non b) with its regulated 14.5v power from a torroid would address most of my criticisms of the 6b, so long as a decently matched speaker is chosen, or perhaps a better quality smps at the same 14.5v would also do the same.

I think, with the right speakers, I could well be happy with an amp6b, but I also think the standard amp6 running from a torroid is a better bet although I will admit I've not heard one yet.