Let's give my pensil 10.3 a bit more grunt!

[Crimson87]

Hi all,
almost a year ago i built a pair of pensil 10.3 which i'm really in love with... I was a complete newbie to woodworking, so my cabinets came out a little "eww" but they do sound (almost) perfect to me.

My system:
Thorens TD160 with rega rb300 arm
Graham Slee Gam-Amp 2SE pre-phono
My pc with an Asus Xonar Essence ST card for flac/wave files and CMP2 player
Yaquin MS-300B 8w p/c integrated amp
Pensils 10.3

My listening room is not huge and far from ideal as it's 3,5m x 3m.

Now to the "problem", after an "honeymoon phase" about a year long i start to sense a bit of lack of bass, not in term of extension but in terms of "slam", so i was thinking to build a subwoofer.

I want something fast and not boomy so, given the fairly small room, a sealed sub may be a good idea, I'm I correct?

After a bit of research i have found this:http://www.diyaudio.com/forums/markaudio/228317-subwoofer-augmentation-alpair-10-2-a.html

so it seems like a sealed CSS SDX10 sub would be good place to start...

Probably it'll also need some kind of amplification...

My amp doesn't have any way to connect to a power amp so i need an amp with a "speaker line in", probably something like the yung SD300 or the dayton SPA 250.

Do you have any project/advice/hint?

Thank you and sorry for my bad english!!!

 

[chrisb]

If you're looking for the biggest overall gain in slam and dynamics, arranging for some type of HP for the amp driving the Alpairs would be time well spent.

The Dayton has a rudimentary HP filter on the speaker output (i.e. via 220mF EL cap - so you'd get an effective 6dB / octave at 90Hz with the 10.3)

There are probably dozens of candidate for the woofers, and a 10" or so sealed sounds like a good option - Vifa / Peerless or Dayton's own brand are popular for this type of application

 

[Octavia]

+1 on the potential of a high pass filter to help integrate a subwoofer and get the most out of any full ranger

 

[Octavia]

also i think with a high pass filter your 300B amp might have some more breathing room driving the full ranger

 

[vinylkid58]

Yaquin MS-300B 8w p/c integrated amp
Pensils 10.3

My listening room is not huge and far from ideal as it's 3,5m x 3m.

I'd just get a bigger amp.

jeff

 

[chrisb]

also i think with a high pass filter your 300B amp might have some more breathing room driving the full ranger

Definitely agree with that, but I don't think the Yaquin has a "processor" loop for easy insertion of HP filter, and he's using multiple sources and no separate line/pre-amp stage, so it can get a bit trickier. It would take some minor internal surgery to add a pair of caps after the Yaquin's volume control to provide the necessary filtering - relatively easily accomplished in PtP wiring, but can be more onerous with all PCB construction, which could the case here.

And Jeff's approach is not without merit either

 

[Crimson87]

First of all thank you!

also i think with a high pass filter your 300B amp might have some more breathing room driving the full ranger

Adding an Hp filter to the yaquin PCB seems a "little" complicated, I have found the schematcs online: http://www.4tubes.com/SCHEMATICS/BY-BRAND/China-Brands/YAQIN/Yaqin-MS-300B.jpg, maybe it's easy and i just need directions who knows...

I'd just get a bigger amp.

jeff

it may seem surprising, given the humble yaquin origins, but i still have to find something that sound better in that price range (i paid 400€ for it). It's mids and highs are so detailed and the bass is deep but maybe a little uncontrolled. While listening to jazz, acoustic, prog rock or even "rage against the machine" i get > 95 db at my listening position, i find it pretty loud and so does my neighbors (i live in an apartment). My average listening level is about 80-85 db, but i will try some more powerful amps.

i dont' listen to synthesized and highly mass produced genres that contain ridiculous amounts of exaggerated bass and i don't want to tear the building apart with HT explosions otherwise i would have kept the klipsch i had before the pensils. i just want some more "body" for the bass guitar E string, not too much as with the klipsch but a little more than now.

Maybe I sould have gone with the FAST route from the beginning but i wanted to keep it simple being my first build...

 

[JoeyGS]

The uncontrolled deep bass is a sign of inadequate power from your amp. I would tend to agree on, at least, trying on a more hefty power amp. Would be good to borrow first before buying.

I have tried running a 150watt per channel gainclone on a pair of 10p in a pensil enclosure ...... and you get all the grunt you need without any sign of distortion. The bass was full and articulate with effortless sound coming out of the pensil. No need for subs!

 

[chrisb]

For less than the cost of a pair of cheap 300B output tubes, you could find something like a Yuan Jing TPA3116 - a very decent sounding amp. I'm driving my upstairs speakers ( Mark Audio CHBW70/ERT26 MTMs with one, and it has all the power I could need for SPLs in the low 80s at max, in a 400 sq ft open plan living / dining / kitchen area.

The only downside to many of the budget amps of this class is the number of inputs - some may have on board DAC of dubious quality and multiple digital inputs, but usually no more than analog input . The upside of that is that they're so fricking cheap that a pair of them for bi-amping, and a small line stage / pre-amp can still be less than a tube SET.

Am I saying that a class D amp would satisfy all listeners more than a 300B or 2A3 SET, or EL84 P/P pentode - pick your absolute favorite tube - amp? of course not, that'd be silly

 

[markaudio]

Hi all,
almost a year ago i built a pair of pensil 10.3 which i'm really in love with... I was a complete newbie to woodworking, so my cabinets came out a little "eww" but they do sound (almost) perfect to me.

My system:
Thorens TD160 with rega rb300 arm
Graham Slee Gam-Amp 2SE pre-phono
My pc with an Asus Xonar Essence ST card for flac/wave files and CMP2 player
Yaquin MS-300B 8w p/c integrated amp
Pensils 10.3

My listening room is not huge and far from ideal as it's 3,5m x 3m.

Thank you and sorry for my bad english!!!

Hello Crimson (Guys).
I'm a 300B user myself (2 custom amps). Neither of mine would be described and "bass generous". We do know that Alpair 10's are bass capable (within common sense operation) and given Dr. Scott designed the Pensil 10's to go low (sub 40Hz from my memory)it maybe more an issue to do with your set-up and room size.

I'm not sure what you'll gain by adding woofers, subs or anything similar in your relative small room size (apart from irritating the neighbours).

Along with the other advice being given, could I suggest the following:

1 - Experiment with the damping material inside your Pensil boxes. I've used less than Dr. Scott initially recommends with pleasing. He does say adjusting the damping material volumes is likely needed as room size and acoustic conditions vary.

2 - Think about going to a more powerful amp. 300B's aren't known for "bass" appeal. They have qualities in other areas that appeal to a particular audience.

I have variety of amps, from SET valve (tube) amps to Sansui and Accuphase class A/B's. Each brings something different to the listing experience

The main thing to remember is your room size is moderate, the Pensil 10's more than adequate for it, so its more a question of "fine tuning" your set up, rather than dong something completely new. Unless you fancy making a new project

Thanks
Mark

In the meantime guys, I've escaped from my latest stay in the hospital, some minor surgery and no observable decease progression. I remain short on energy, varying daily, but this is to be expected. Thanks again for your on-going best wishes and support

 

[JoeyGS]

Maybe another thing to consider ....... have the drivers been run for 400 hours? My experience, as originally suggested by Mark, is that all frequencies especially the bass becomes articulate and more pronounced as the drivers reach the 400 hour mark. With less than 400 hours, I can say that it was a bit shy. I almost wanted to pair it with a sub, but when broken in, its best on its own. (Of course until you get the best sub to much the speed of the MA drivers and you have plenty of music materials needing the low low bass)

 

[Crimson87]

Hello Crimson (Guys).
I'm a 300B user myself (2 custom amps). Neither of mine would be described and "bass generous". We do know that Alpair 10's are bass capable (within common sense operation) and given Dr. Scott designed the Pensil 10's to go low (sub 40Hz from my memory)it maybe more an issue to do with your set-up and room size.

I'm not sure what you'll gain by adding woofers, subs or anything similar in your relative small room size (apart from irritating the neighbours).

Along with the other advice being given, could I suggest the following:

1 - Experiment with the damping material inside your Pensil boxes. I've used less than Dr. Scott initially recommends with pleasing. He does say adjusting the damping material volumes is likely needed as room size and acoustic conditions vary.

2 - Think about going to a more powerful amp. 300B's aren't known for "bass" appeal. They have qualities in other areas that appeal to a particular audience.

I have variety of amps, from SET valve (tube) amps to Sansui and Accuphase class A/B's. Each brings something different to the listing experience

The main thing to remember is your room size is moderate, the Pensil 10's more than adequate for it, so its more a question of "fine tuning" your set up, rather than dong something completely new. Unless you fancy making a new project

Thanks
Mark

In the meantime guys, I've escaped from my latest stay in the hospital, some minor surgery and no observable decease progression. I remain short on energy, varying daily, but this is to be expected. Thanks again for your on-going best wishes and support

Thanks for the answer Mark, let me start by giving you my best wishes for your medical issues.

The idea of a sub was definitely a stupid (probably newbish) one... Yesterday i had an amplifier comparison session, the contenders were a dayton dt-100 and a NAD c325bee against my yaquin, the results (basswise) were staggering.

Dayton
Pros:
I first listened to the dayton and the 20 extra W were immediately noticeable, the bass was fuller and controlled, the "slam" was back in spades (maybe even too much )compared to the yaquin and the overall performance was enjoyable especially with rock music like dire straits. What impressed me the most was the soundstage, it was much wider than with the yaquin and also the tonal balance was very similar, something i really like.

Cons:
Mids and highs frequencies wer less refined compared to the yaquin, there was some "grain". Instrument separation wasn't as good as with the yaquin in jazz or acoustic music, in rock music the performance was much more controlled.

NAD
Pros:
The nad was the most powerful of the 3 (50W @ 8 ohms) and the performance, always basswise, was simply stellar. The bass was deep, controlled and really articulated, i listened to a wide range of genres and it was able to withstand to anything playing loud (85-90 db) with the volume knob never passing 12 o'clock . The bass performance with this amp really impressed me, no need for sub or other woofers you were absolutely right. The drums in High Life (Jazz at the pawnshop) were absolutely impressing, never heard them so good.

Cons:
The other part of the audio spectrum , mids and highs were not yaquin good, and, especially the highs, were a bit shouted. Probably it's me being used to the yaquin's sound but i preferred the Dayton tonal balance over the two.

So in the end you were right, pensil's bass is MORE than enough and, given the results of yesterday's test, class D seems like a viable option.

I've read a lot about the Hypex UCD 180 being the top of the class and i always wanted to try them, the test confirmed that they could sound good with my pensils, do anyone here use them?

Those modules are about 50W with 0.01 THD at 4 ohms (there is no graph in the datasheet at 8 ohms).
I know i'll have to trade a bit of the mid performance for the bass perfomance even in the best class D implementation...

what do you think?

 

[Octavia]

It would be nice to choose an amp that gives you both the bass you want and that lit from within mid's and high's with a soundstage that reaches to the original acoustic and a quickness that breathes life like the suddenness of the real thing. Which amp is that? If you find it let me know, I'm looking for it too. If I were you since you like other attributes of your 300b amp why not consider a push pull tube amp. Not that I am any kind of expert but I have heard a lot to like in some EL84 amps.

 

[chrisb]

2A3 or 6BG4 push pull would fit that description nicely. Years ago Brian Cherry offered something - Joplin, I think it was, that for not a helluva lot more than pair of Bottlehead 300B SET kits at the time was very listenable.

I've heard a few 300Bs, and owned a pair of Wright Mono Blocks for a while, but ultimately found that between the two, I preferred the 2A3.

 

[Crimson87]

2A3 or 6BG4 push pull would fit that description nicely. Years ago Brian Cherry offered something - Joplin, I think it was, that for not a helluva lot more than pair of Bottlehead 300B SET kits at the time was very listenable.

I've heard a few 300Bs, and owned a pair of Wright Mono Blocks for a while, but ultimately found that between the two, I preferred the 2A3.

300B push-pull it's going to be expensive, way more than what i want/can spend.

i want to try something different, that's why i thought to buy the ucd 180 modules. many reviews says that their sound can be compared to a triode in mids and highs but with a greatly controlled bass.

reading around i have found out that chrisb had some, how do they sound?

my diy skills are really basic so i need something simple...

 

[chrisb]

if you're talking about the ucd modules, I think it was Dave that sourced some, and we just never got around to building them - amazing how lazy one can get in their dotage - 63 last December for me

Never did hear a 300B push pull, buy at least 2 different 2A3 / 6BG4 variants (Brian Cherry's Joplin, and a stunning bread-boarded, home brew widow-maker by our own nerdorama - details posted somewhere)

 

[Octavia]

I'm pretty sure that dotage doesn't set in until 83

 

[kp93300]

Hi Crimson87,
You might want to consider a class D amp based on TPA 3116 chip.
I have several powering the 12p in superpensil. It sound spectacular in all aspects .
There is a group buyongoing for for the Weiner amp --a class d amp based on TPA 3116.
Donot let the low price deter you from purchase. These are not toy amps.
regards
kp93300

 

[chrisb]

I'm pretty sure that dotage doesn't set in until 83

I guess that depends on how your weekend went - all day in the shop on Saturday, then a family BD on Sunday - 8 kids under 5, and the assorted extended family - the second longest and cacophonous 2.5 hrs in recent memory ( "Prometheus" still holding first place on that list)

kp93300: yup the TP3116 is probably the current giant killer