Been refurbing my Impulse H2 speakers during lockdown...
Heres a ‘before’ picture.
https://i.imgur.com/kFP2vgE.jpg
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Been refurbing my Impulse H2 speakers during lockdown...
Heres a ‘before’ picture.
https://i.imgur.com/kFP2vgE.jpg
:popcorn:
Love the sound, and short of a lottery win probably endgame for me.
Not so much the look in my room?
70s church organ Teak not really working for me, so what better time to start my “cunning plan” when off work during lockdown.
So what’s the Plan?
Modernise the look, make them fit better in my room and maybe improve the sound along the way if I can?
Specifically looking at the following:
VISUAL LOOK
* Convert them into the “white version” that was never made to fit the look of my room and make the huge cabinets less imposing.
So all panels, horn enclosures and acoustic cloth all need changed to white.
All materials chosen and sorted, will blend in much better in the room even despite the speaker size I think.
https://i.imgur.com/qtiF54W.jpg
Drew up some sizes for replacement cloth, panel sizes etc. To let me buy in what I need.
https://i.imgur.com/HOXFAz4.jpg
https://i.imgur.com/cZcchx8.jpg
PERFORMANCE
* Sound fantastic as is, but any improvements I can do along the way?
Decided not to go down the route of changing the crossovers, as I don’t want to change the basic character of the sound.
The internal wiring wiring between crossover and drive units doesn’t fill me with the warm fuzzies...
Very stiff thick solid core with evidence of oxidation along the cable length, the solder joints seem less than ideal too.
The cable may have been good at the time, but the speakers came out in 1991 so nearly 30 years old!
I use Duelund DCA16GA tinned copper stranded wire in cotton and oil as my main speaker cable and it’s the best I’ve had in my system, love it’s “Tone”, it’s just right.
Decided to internally rewire the H2’s with the same stuff, though after some research I’ll be using the same 16GA for mid and top, thicker 12GA for the bass.
Thinking synergy with using the same cable throughout the speaker chain?
Once speakers are done and had some time on them, I’ll try some 12GA as my main speaker cable too and compare.
Comparison of old and new internal wire:
https://i.imgur.com/wKBRTyF.jpg
OTHER POSSIBLE PERFORMANCE IMPROVEMENTS
One of the changes the successor to the H2 had was how the downward firing bass horn interacted with the floor, giving sometimes inconsistent results...
I found spiking straight into carpet wasn’t as good as putting a stone slab under the speakers, so some truth in this.
The successor basically had its own “floor” built in standardising the result in different rooms.
An acoustically damped metal plate 2” from the mouth of the bass horn better controlling how the bass interacts with the floor.
I won’t be doing THAT but I will be doing similar.
So interaction with the floor can be improved.
To do this I’ll be disposing if the old (and rusty!) floor spikes and fitting “outriggers” from a Company called Soundcity in the US, who specialises in this stuff.
Will be replacing the basic spikes with IsoAcoustics Gaia speaker footers.
The IsoAcoustics stuff really works, recently got a set of their footers for my Turntable and works great.
So basically something like this:
https://i2.wp.com/soundocity.com/wp-...40%2C480&ssl=1
but with the spikes replaced with far better IsoAcoustics speaker footers. The do “spike plates” for the feet to sit if you have carpet, to spike through to the floor below.
https://www.stereo.net.au/forums/upl...f5f158a867.jpg
The “improved” H2’s had a damped metal plate built in near the bottom of the speaker to better control the bass firing down?
I’ll be experimenting with putting a similar damped plate of some kind on the floor or maybe even a few inches above it below the downward firing bass horn, to try and recreate that improvement.
So,
Thats then Theory...on with the Practice! :D
'Internal requiring' ooh err missus..
Take it the auto correct kicked in and you meant internal rewiring.
Nah..he probably meant that 1st post Alan :lol:
:lol: Yeah, typo-tasticQuote:
Originally Posted by Firebottle
https://memecrunch.com/meme/A9LD7/yo....jpg?w=620&c=1
Yup, even with a quick blast of white, concept approved. :thumbsup:
Time to start destroying them!
Cabinets need to be disassembled, drive units and crossover removed, all spikes and cloth to be removed.
Basically stripped right back to their shells to let the refurb start.
https://i.imgur.com/EE65KJM.jpg
Spikes off first...to let me remove grill cloth.
https://i.imgur.com/sbNT9Ku.jpg
Mid horn removed, cloth being removed.
Too late to change my mind? :D
https://i.imgur.com/9XgDk2D.jpg
Cloth and side trim mostly removed
https://i.imgur.com/k5gRddn.jpg
https://i.imgur.com/aHLo0v3.jpg
While the H2’s are out of action brought through the Dali’s from the 2nd system to keep music going, really give an idea of the size of the H2’s and how a white speaker is much less imposing in the room.
https://i.imgur.com/7cgb8K4.jpg
We're big fans of white speakers, they blend in more if you have light coloured walls. You're doing a champion job so far which I'm sure will look great in your room.
All speaker cloth and panels removed, keeping the old stuff as a Template to cut white cloth to size before refitting.
https://i.imgur.com/XFbYNhE.jpg
Both speaker cabs stripped down, mid horn removed and ready to remove the drive units and crossover.
Over the life of the speaker the curved side panels had came loose in places, showing panel gaps where it had came away..so decided to remove them and reglue.
A lot of cleanup required...
https://i.imgur.com/smdLycs.jpg
Rear panel will need repainting from black to white...
https://i.imgur.com/Z9KZho7.jpg
Posties been...
https://i.imgur.com/iONudOH.jpg
https://i.imgur.com/ewcQYQg.jpg
https://i.imgur.com/vbnrjea.jpg
With the IsoAcoustics feet and the Collaro red mat it’s quite the improvement, even over how good the P10 sounded originally.
Quite different from the supplied Rega mat, thinner and more compact, can tell it’s a different material altogether.
Happily no VTA issues, just plonk n play.
Grips better to the platter too, less prone to lift off with a static-y LP.
Good stuff.
All about getting the most from the kit.
Love it when a plan comes together.
A vinyl day today I think.:)
Looks very smart.
Really lifts the deck that
Aye,
It does look good on there I think?
Splash of colour, bit of punch and a good contrast against the white.
Like the retro logo too.
Yes the logo makes it.
Really like the look of your P10.
My second TT was a Collaro 2010 (or it might have been a 4T200). It was a sort of "poor mans 301".Quote:
Originally Posted by Macca
https://www.vintage-radio.net/forum/...8&d=1496421023
I re-sprayed it semi-matt black, resprung the motor, replaced the switch suppressor and fitted it with an SME 3009 II arm. It would have looked good with the new Collaro mat.
Would look great on there.
Those decks were supposed to be very good.
Bit of tweakin’ of a Thursday...
On clearing out my Hifi bits n bobs drawer, came across a spare Synergistic Research Blue fuse I used on my (now sold) Transporter.
Turns out its rating compatible with my PS Audio BHK preamp, so in it went.
https://i.imgur.com/2DYfGbI.jpg
jobs a good ‘un. Nice improvement over stock fuse.
Have them elsewhere in my kit, and they do what it says on the tin.
Also, been playing with isolation feet, having a glass shelved rack’s not the ideal, but having sorted my turntable support recently, was looking at my digital source now, the Oppo 203.
This is my Roon Network renderer as well as the Hub for Netflix, Youtube and the like...all sound goes through the Oppo.
So worth tweaking more out of it if I could.
Had some bits lying around tried a few combo’s and settled on these.
3 part footer,
https://i.imgur.com/QEhKQtI.jpg
SoundDampedSteel “constrained layer damping” plate
https://sounddampedsteel.com/hifi/
RDC Cone “Cups”, sat on top of the SDS plate for 2 layer isolation from the glass shelf.
https://www.analogueseduction.net/is...ack-of-4-.html
The top of these (conveniently) are recessed to fit onto the matching RDC Cones.
I tried the Cones with them, but weren’t as effective as using the recess in the Cup to fit a ball bearing in.
Taking an idea from the Naim Fraim Hifi stand, a ball bearing gives the smallest point of contact under your kits casework and offers really good decoupling.
So with two Additive layers of vibration absorption, topped off with a good way to decouple your kit from the surface...job done.
good job getting stuff off glass gary.. it causes issues ive found...
Made a really good improvement Grant, better sound all round.Quote:
Originally Posted by struth
Oh,
replaced the steel ball bearing with a Silicon Nitride ceramic ball bearing today, they are same as the ones used in the mega spendy Stillpoints.
Always good to trickle down mega money design tweaks to your own homebrew ones if you can!
Old
https://i.imgur.com/eNWVboK.jpg
New
https://i.imgur.com/fgftg0f.jpg
Better than the steel bearings, speakers doing a better job of disappearing and music has more texture and timbre to it.
Better music,
all from spare bits I had lying around too. :D
Was going to get more IsoAcoustic Footers for under my Dac and Preamp, but will save a chunk of change and make these up for under them instead.
Can’t see the IsoAcoustic feet bringing much over the improvement I’m getting here.
The Games afoot...
new feet is it?
naa.
Like yourself a big box delivery.
I've sold both Rotel power amps so... :eyebrows:
Hows your new amp coming along Grant, the volume getting better?
ok the amp from italy thats not italian :lol: yup getting used to it now. was just odd how youve gotta go so high with these speakers.. i wonder if less sensitive speakers need it up a lot more..Quote:
Originally Posted by Gazjam
Aye, that one. :)
Thought it had gone AWOL somewhere over the Atlantic, had sourced some alternatives and given up on it, but showed up in Parcelforce tracking this morning as having arrived in UK.
Soon after was out for delivery today, so an unexpected result.
Funny how things work out sometimes, fingers crossed it wont be in bits or have fish stuck in the box!
Efficiency is Efficiency , speakers kicked out a hoolie with 8 valve watts so should be fine I'd have thought.
It's only the system gain structure Grant IMO, as long as you can get the sound level you need it's good.Quote:
Originally Posted by struth
Changed a pot for a stepped attenuator in a high end preamp and the same happened, had to rotate the volume knob more for the same volume level.
its a Burr-Brown analog PGA2310 volume control chip. he PGA2310 possesses two main components; a set of resistor networks and an op-amp output stage. (An op-amp output stage? We’ll come to that.) The resistor network allows for an amazing 0.5db steps of fine control with channel matching within 0.05%. Compare that to conventional motorized volume controls which can only match channels to 7-10%.Quote:
Originally Posted by Firebottle
Burson’s secret sauce is setting the PGA2310’s op-amp output stage to unity gain so it essentially acts as a purely resistive volume control. This arrangement avoids any coloration the op-amp output stage may inject into the audio signal.
Sounds like a unique way of doing it, good stuff Grant.
As Alan said, as long as you get the volume you need.
In other news...
Posties been.
https://i.imgur.com/NzL5QYO.jpg
https://i.imgur.com/h2xMjPT.jpg
Densen DM-30 power amp.
https://i.imgur.com/79OyXfo.jpg
https://i.imgur.com/zr0LyYQ.jpg
Have the matching DM20 preamp, will try it with that, though I don’t use that pre in my main system.
Supposed to be a great pairing, so will see how that goes. Need to try it just never know.
Going to plumb it in and leave it to percolate for a couple of hours.
Recently recapped and serviced and sounding as good as ever, should be a very nice bump over the wee Rotel I had been using.
Fun.
anyways, whaeres the pictures then :eek:
double boxed, or is there 2??Quote:
Originally Posted by Gazjam
Double boxed and thankfully no Atlantic fish inside)
Quote:
Originally Posted by struth
Looks very smart with the matching Preamp.
I remember polishing out the acrylic front panel of the pre to get it looking good, the power amp looks brand new!
https://i.imgur.com/0yPt58K.jpg
Anyway,
on to wiring it up then some music.
to be continued.
a nice match gary
So how does it sound?
Sounds superb, much better than before.
On one channel, the others dead.
Speaking with the Seller just now.
hes a reasonable guy, just not sure what my options are given international nature of sale.
Any suggestions via PM please?
Paid via Paypal.
That's a shame. PayPal will cover you tho
Does it take a while for PayPal turnaround?
Seller has offered to refund repair cost if I take to local Technician.
seem a fair proposal?
No idea mate, I just know your covered. As you say if it's a gen offer then might be way to go
It’s a gen offer, and the least stressful option, given the international angle, shipping time etc.
A Pisser for sure, but is what it is.
Worse things happening atm.
Cheers Grant.
Interestingly the PGA chips are what I am using now, incredibly transparent.Quote:
Originally Posted by struth
However they have to be treated to the right in circuit conditions to achieve their full potential. I do wonder if that is the case in the Pathos amp.
It needs very low noise supplies and low source impedance to sing.
Thread drift, sorry Gaz, as you were.
No worries Alan. :thumbsup:
Sorry to hear about the missing channel, very frustrating I'm sure. PM sent. :rolleyes:
Taking the amp into a local reputable repair Tech. tommorow.
The Seller (A good guy) has agreed to foot the bill.
All’s well, but ends well.
Must say, the Densen did sound a bit ‘flippin’ crikey’ tremendous on the one channel, so all good going forward.
Good, hope its trivial..
Aye,
Same Grant.