Markaudio 12P plus ACA amp

[Ugg10]

Quick Questions -

Will the Amp Camp Amp class A amp (8w) drive the 12P in either a Pensil or a Marken box. Will I need to mono (15w) the amps to get the best sound ?

Not looking for concert levels but for decent sound level in a small ish (10ft x 10ft) room.

Thanks in advance.

 

[Scottmoose]

Will the Amp Camp Amp class A amp (8w) drive the 12P in either a Pensil or a Marken box.

Yes, you should be fine. For the most part they'll be ticking over (well, a little more, but not excessive based on what you say about levels)

Will I need to mono (15w) the amps to get the best sound?

'Best' is a floating point that varies depending on what the individual means by it, so to a point YMMV. You won't need to to drive them; you may get some improvements by running as monoblocks however, so if you can afford to do so, it sounds like a good qualitative option to me.

 

[Ugg10]

thanks @scottmoose, much appreciated. Don't suppose you know if you can get just he circuit boards in the UK as importing the basic kit make it a very expensive bag of parts ($119 + P&P $25?) / 1.3 [exchange] * 1.2 [vat] = £132.

My only other option is to hard wire on a board ???

I know there are Chinese ripoffs but would prefer obviously to use an authorised route.

 

[twocents]

Don't suppose you know if you can get just he circuit boards in the UK as importing the basic kit make it a very expensive bag of parts ($119 + P&P $25?) / 1.3 [exchange] * 1.2 [vat] = £132.

Try Jean-Pierre in Germany - I am sure he can help you:
My first GB

 

[GASCo]

For what it’s worth, Nelson himself doesn’t care where the boards are coming from if you need help and assistance of the forum. It’s an open design after all.

I’m with you that would be great to support the forum but unfortunately there is no bare pcbs available for a while.

Just be careful that the Chinese pcbs are not a perfect copy. You need to change a couple things based on the schematic they use, missing one cap and r15, god knows why...

 

[toobhed]

I really enjoy the combination of my old ACA (5w, 19vdc PS) and my regular (not super) MA 12p Pensils. My room is larger than what you indicate and there is no problem with volume or headroom. They're a great combo, go for it!

Mario

 

[Ugg10]

Many thanks @toobhed, what was the bass like, not expecting it to shake the foundations, any idea how low it went and was it tight/loose/wholly/ any other adjective you can use to describe it?

 

[toobhed]

Subjectively, the bass was just fine....and very adjustable depending upon the amount of stuffing used, how close the speaker is spaced to the back wall, etc. Not as tight of bass as a good two-way's woofer, but a far better sounding speaker than many many two-ways. The highs are outstanding for a cone this size and with very little beaming...to be sure a great cabinet design by Scott...and easy to build.

I recall ending up with somewhat less stuffing than the original recommended starting point from the plans. I know others may differ, but I find the 12P about perfect for my tastes, not as detailed as my MA-A7m Pensils, but more efficient and a bigger (more air moved) sound.

...just go for it and build!

Mario

 

[planet10]

From the many months i spent with the original ACA & A10p Mar-Ken (which give up a dB to A12p) in my large room (24x36 with a 27 ft peaked ceiling — ≈ 250 m³ if you are not trying for concert levels you will be fine,

dave

 

[xrk971]

You might try an Alpha 20 amp - 20w and also SE Class A but no unobtanium 2sk170’s needed. Alpha 20 is a true “zero adjustment” Class A DC-coupled output amp.

Aksa Lender P-mos Hybrid Aleph (ALPHA) Amplifier

 

[Ugg10]

Thanks all again for the comments.

@xrk971 is the alpha 20 amp similar to the clones badged as “a30” on eBay at 30w class A?

 

[xrk971]

Those A30’s are a totally different amp and have been around way before Alpha came out. The Alpha is a new topology by Aksa but using the Pass Aleph CCS. As far as I know, no one on eBay has cloned the Alpha yet!

 

[twocents]

You might try an Alpha 20 amp - 20w and also SE Class A but no unobtanium 2sk170’s needed. Alpha 20 is a true “zero adjustment” Class A DC-coupled output amp.

And of course a worthy preamp to match: AKSA's Lender Preamp with 40Vpp Output
Man, this preamp is also something really really special - I am currently using it with my ACA and they drive my 88dB Tannoys louder than I will ever need.

 

[Ugg10]

Thanks again, this forum never fails to deliver.

Thanks for the preamp info @twocents but I am ok for the front end as I run an Audio GD nfb3.1 dac, fed by a chromecast audio into a SM PRO M-PATCH V2 passive preamp. Currently this then goes to a pair of Mackie HR824 active monitors and a B&W ASW810 sub but thinking of going full range for a bit more refinement with this combo possibly with the amps running like an active in a plinth if I can arrange for some inflow or make a feature of the heat sinks.

 

[xrk971]

If you go with Alpha, it already has Aksa Lender Preamp built into the front end. Thus, it comes default with 29dB gain which can be driven by anything.

 

[Ugg10]

Thanks for the info, my dac puts out 2.5v and I use the passive preamp (has interchangeable potentiometer and 12 position ladder attenuator, using the latter), will the alpha take the dac output straight off and how does it control volume (note to self must read the full alpha thread when I have spare evening).

 

[xrk971]

Yes, Alpha can be driven straight from 2.5v DAC. Just add 10k pot between to control volume (or your stepped attenuated).