experience with the Pencil's 7 and some questions..

[fxs]

Hi all. Recently i finished a pair of Pencil 7 loudspeakers :d... i have several questions given im not all convinced about the sound..

Im driving the pencils with a harman entry-level receiver(avr 154, the multichannel models), this receiver has good reviews about quality sound, even i haven't compared to anything else. The source is a harman dvd/sacd player, with excellent reviews over there. It's about 40w max per channel at 8 ohms, not specified at 4 ohms (the impedance of the Pencils 7 right?).

What i'm listening is kind of a strange sound.. i would say it has a high resolution, detailed, and with nice soundstage imaging (i haven't fully optimized the speakers positions yet), but without strong/definite colours.. it's like seeing a high definition movie in black and white(great resolution, detail, but like having no colour). I listen music generally with studio headphones (senheiser model), so i´m not missing any fake colored sound, i'm talking about real coloration of the instruments :d

Before blaming the amplifier (i think the source is very good), i would ask some things, and make some observations, about the cabinet implementation:

- I noticed the stuffing material quantity has a quite critical impact on sound..i used a chesky test cd for adjust the material (the tracks have indications about how should sound the complete system), and notice that a few less or more (i'm using "normal" density polyfil) change the sound from an overdamped/lean sound to a very live and realistic one, with full and loud bass (like if i had tuned the speakers to some exact point). I set the material up it sounded better to me, and quite coincidentally with the chesky cd recomendations. Like i said before, the sound is quite detailed, high resolution(a lot lot better than the senheiser headphone detail /soundstage), but like in black&white :s

- The cabinets are built with natural pine, 18 mm width. Given natural wood is a little more harder to cut, i notice after the cabinets were built, that the port extension is a little shorter, like 1-2 mm less (from the original 35 mm indicated on the planes), and not exactly even across the width of the cabinet. Could be the cause of the grey sound?

- The wiring is awg 14 (internal) and the external cables are awg 18 (about 1 meter long)

- The drivers are not fully inside the front panel, are like 1 mm evenly protruding over the front panel, and using the supplied mounting rubber.

I hope someone (scott? planet10?) can give some diagnosis about the situation described. I want this Pencils really shinning . Thanks

[markaudio]

Hi Fx,
I'll leave others to comment on tuning Pencils as there's plenty of practical experience.

The Harman is a budget priced HT amp. Its not going to give the quality output needed to optimise the Alps. Not wishing to hurt your feelings but its a poor choice for Alp7's. There's several posts from me advising Alp7 users not go low end on source and amps when mating to Alpairs. Could it be good for CHR's and CHP's possibly but its a No-No for Alpairs.

Source? Which model Harman DVD, SACD? Also, doesn't sound promising.

You may need to tune the Pencil (add or take out damping) but you'll never be sure of the outcome until you get source, cables and the amp sorted out. Time to get your credit card out and shop around for a nice tube amp and possibly a vintage Mofset if you're into solid state. Concentrate on a really good source. If you're like me, still wedded to CD's, look out for really good used Accuphase DP's but they aint cheap. Aslo Denon DCD S10's, Teac VDRS's (not the low models), some of the nicer Pioneers to name but a few.


Cheers
Mark.

[fxs]

Thanks Mark, i'm also thinking on change the amp. The source is the dvd 48 model (top of the line cd/dvd player a couple of years ago). I suppose the cabinet's minor imperfections shouldn't cause the pale sound, but it's better to ask :d

[planet10]

fxs,

Mark has already mentioned the amp... if it has any warts (likely) the A7 are going to savagely reveal them. This is where CHR, EL70, or CHP70 can be more forgiving.

I wouldn't worry too much about the terminus area, it should have minor impact.

I've been listening to a couple well built solid Douglas Fir boxes (one with A12, one with Fostex FE166) and both are lovely sounding, but the solid wood adds a bit of "romance" to the sound that is absent in a reference plywood build.

I'd also try substituting the wire. Since it is usually easy to get a hold of (and often free) try some single 24g strands (solid core) from a chunk of CAT5 network cable. Both internal & external. That will give you a different point of reference from which to work.

A 1 mm bump from a not quite deep enuff a rebate is smaller then the raised lip from the bezel cover so is unlikely to be of great concern. This can be remedied with a layer on top of the baffle of the appropriate thickness, felt or cork for example.

dave

[fxs]

What do you think of this tube amp? Zen Triode SET kit amplifier model ZKIT1
The power is about max. 2.3 w/channel at 4 ohm.. would be enough to drive the Pencils 7 to respectable loud levels? I´m sitting about 2-2.5 meters from the speakers

[zman01]

Fxs,

I don't have an Alp 7, but have other MA drivers. With my limited experience, more watts and a bit more hearoom would be better; a good push pull amplifier maybe with ~15 watts? I have used the CHR-70 with with SET, SEP, and a higher watt PP, and I felt that the driver appreciates the extra watts provided by the PP amp, specially on the low end. Make no mistake, the 3.5 watt SET can drive them to moderate volumes with lovely detail, but probably not near to the full potential of the speaker.

I would recommends that let the experts chime in before you take your call.

-Zia

[jimbro]

How many hours do you have on the drivers?

[chrisb]

Originally Posted by fxs

What do you think of this tube amp? Zen Triode SET kit amplifier model ZKIT1
The power is about max. 2.3 w/channel at 4 ohm.. would be enough to drive the Pencils 7 to respectable loud levels? I´m sitting about 2-2.5 meters from the speakers

I've heard several production versions of this design (with tube rectifier ), and built several of my early scratch builds based on the circuit. Quite simply a delightful little amp that punches way above its weight class - but a single in stereo mode might not be enough for some folks. When bridged in mono, it's another story. IOW, definitely a contender if you're DIY inclined.


but you're the best judge of how much power is enough

Originally Posted by jimbro

How many hours do you have on the drivers?

Yes, they'll need probably a couple of hundred hours to fully settle in

And yes, they are ruthless in revealing the nature of all upstream gear and source material. I normally run a HT front row 3 of Alp7 with a Denon AVR1610 (still a budget level machine compared to higher end models in their line, Anthem, Outlaw, etc.) . On a couple of occasions I've plugged them directly into a EL34SET or EL84 P/P amp / Jolida CD player system and the difference isn't subtle, but for movie / TV viewing I stick with the Denon, and just accept its deficiencies. Even if I could muster the interest to conduct the experiment, this receiver doesn't have line level outputs for all channels, and I don't have enough channels of tube amp with identical power/voicing characteristics to avoid messing things up.

[fxs]

about the break in time, the alps have a little more than the 100 hours recomended.

[chrisb]

Originally Posted by fxs

about the break in time, the alps have a little more than the 100 hours recomended.

well, before fiddling about any further with adjusting stuffing fill in the boxes, would you have access to another system of higher resolution (say a friend's "hi-end" 2 channel system) to eliminate source and/or amp as culprit?