Orthodynamic Roundup - Page 816

What's the size of the hole in those pads? To you feel a reason for the bad seal? Are they too stiff or what's the trouble?

Nice updates :-)

The hole is 45mm or so, compared to 30mm on the original pads. It's very similar to the original pads in material, stiffness and depth. I solved the seal problem by using the foam circle that came with dt990 pads under the pads - it's more comfortable and seals well now every time, the foam doesn't seem to impede treble at all. Sounds fantastic and has a more open feeling than the original pads, the comfort is not worse and perhaps a bit better too. I'll do a proper comparison of old and new.

sorry if this a little out of topic,

i'm using Samsung P3, and i have woody SFI ortho 120ohm
i need power amp that can drive my ortho (DIY or built-up)

did you have any suggestions for me, what mini-amp that can power up my P3 to drive ortho?

listening to Don's HP-50 on my system...I am listening in disbelief to how good this pair of HP-50s sound..Perfectly balanced, silky smooth midrange, nice treble, adequate bass. All around excellent sounding headphones.
Got to hand it to the zen master..fabulous.

life is all about balance ..dB

The differences between T20v2 standard pads and Chinese ebay pads with dt990 foam (the foam is necessary for comfort and fit):

The ebay pads make the sound less warm in the mids, and listening to a test sweep shows that whilst the t20 is pretty balance either way there is a little more emphasis on lower mids and bass with standard pads. This is just a small matter of emphasis. I expect I could warm up the lower end by altering the damping, but I'm happy as it is.

The volume needs to be turned up a fair bit to get the same volume using the e-bay pads.

But there is soundstage with the ebay pads (unlike standard), a pretty fair soundstage at that, not so far off my '80s 600ohm dt990s, although headstage shows itself a bit more readily than with the 990s. The general signiture is now quite similar to the old 990s (not to be confused with newer 990s), but with ortho silkiness. The soundstage helps instruments separate out, makes music less muddled.

Given that with the e-bay pad I still get a reasonable (if not quite old skool ideal) slam from the bass in DMX Krew's 'DMX Bass' (my electronic bass test), the low end is not compromised. I don't really listen to much electronic music, but rather mainly to jazz and orchestral classical, and for this these pads are a brilliant upgrade.

In comfort it's swings and roundabouts. The new pads are almost but not quite cicumnaural, so there is a bit of pressure on the tops of my ears which isn't great, but the old pads are a bit wearing for long listens too.

edit: to be precise about the soundstage going to headstage - close instruments can tend to sound within headstage rather than soundstage, particularly in front, but further away instruments tend to appear in soundstage quite nicely. Instrument separation is quite nice, not too analytical (my k340s tend to be too analytical - a bit hyperreal).

Pad adapter tutorial

I need to whip up a set of pad adapters for the RP18s and I have the adapters for the Kenwood KH-82s in progress, so I took pics...


Tools of the trade, except the missing steel ruler:





Step 1: Measure the outer diameter of the headphone front bezel, then subtract 2-3mm to account for slight variation when you actually cut out the ring or disc.







Step2: Measure the driver opening. This measurement will carry through the rest of the rings.







Step 3: Measure the OD of the pad mount. In my case I averaged 3 pads, the O2s, the Denons, and the K240s and called it 100mm.







Step 4: Measure the offset for the lip. This will set the OD of the inner spacer ring and give the necessary clearance for the pad to mount properly. This inner ring space is usually gapped to 1.5mm or 0.065" so that's the thickness sheet we'll need for the ring.







Step 5: After you have written down your dimensions you can determine the ODs and IDs of your rings and also determine if you will have enough area to get a good seal on the bezel with just an inner spacer ring or if you will need a third ring to mount to the headphone bezel. In my case the offset for the O2 pad was the largest at 15.35mm on each side and the total distance between the outside of the bezel and the driver opening was just over 25mm, so I will need the third ring to give a large mounting surface for the 2-sided tape.






Step 6: Convert your diameter into a radius and use the steel ruler to set your OLFA hole cutter.







Step 7: Start with your largest OD to determine your spacing requirements on your plastic sheet. Here I'm using clear polyester because it's softer and more flexible, but acrylic, ploycarbonate, polystyrene, or polyethylene sheet will work too. The black dot just locates the center for me.







Step 8: Layout all the ODs and IDs so you can see how the 2 or three rings will look. The first two are the thinner inner rings. The bottom four are on 2mm (0.085") thick sheet for the bezel mount and the pad mount rings.









Step 9: Start cutting! Always cut the OD first. You've been warned. In the pics below I drilled out the center so I could chuck it my drill to sand the OD. Big mistake and major PITA to get the IDs cut out.







Step 10: Sand. The pic below is the pad mount, inner ring spacer, and YH100 adapter for one side of rythmndevil's YH100 to Koss R10 adapters plus the second inner ring for the other ear.







Step 11: Test fit the three rings and try to get the best alignment you can. Mark the ID of all three with a single, double, and triple hash mark for alignment guides when you are gluing them up. Use CA (superglue) to glue them together or you can use 3M Super 77 contact cement if you want or need to change the pad mount ring for larger variations in pad sizes.

Sorry, no pic of that yet.






Step 12: Use double sided tape to mount the pad adapter to you headphone bezel. If you want a really strong bond, use the bumper mounting tape from automotive parts warehouses, but wait until you know you absolutely will not have to get back into them for anytime to come as they will be nearly impossible to take off. It's not permanent, but damn close Skippy. I use a simple 3M double sided tape while tweaking.


That's it. That's all it takes to becoming a pad rolling junkie without having to tear up your precious $35-$130 pad sets.

damn Brian...that's simply amazing work there.. brilliant stuff

The ATH-A1000 pads seem to be a good thing for the maior, but i need to come up with something like that pad adapter

Thanks. I think you'll like my next few projects then because the pad adapters are easy, just time consuming. My other custom projects are not easy.

OT, but I scored a Hallicrafters Model S-38D HAM radio on FreeCycle. Pic below. I'll repurpose the chassis to an amp and replace the tuning dial with clear glass. Hoping an eXStata will fit, but I won't have the internal dimensions until tomorrow when I pick it up.





Heck, it already has just about the perfect number of holes. A volume knob on the left, input selector to the right, the two center knobs removed for jacks. The two slider switches will be replaced with a power switch and pilot light.

Just browsed through Craiglist a bit (always a bad idea) and found a couple more nice vintage receivers for good prices... CR-820 for $95 and Onkyo TX-4500 MkII for $65. Kinda makes me wish I didn't pounce on the 620 but it's cool. Does anyone know if the Onkyo is any good?

Grab the 820 and sell off the 620... Then keep the 820 when you add the 2020...

Thanks for the link... maybe I should join AK. So it was part of a last ditch effort to save Onkyo from imminent doom and later, complete obscurity. Interesting. Does the 0 mark on the tone controls count as defeating them typically, or are they still part of the circuit? I don't use tone controls anyway, but I'd rather not have them messing up the sound.



Edit: Nvm.

Edit 2: BMF, I may consider doing that, but don't know if there are people as crazy as me looking to buy these massive vintage receivers.