"KOSS HV High Velocity Series"

luvmusik

luvmusik

HOORAY !...ELECTRICITY !
Have a pair of Koss HV/1A that have seen better days. Looking for info and help please on the Koss HV and related Realistic line also. These are the TEN models I have seen in the HV line:
HV/1
HV/1A
HV/1APlus
HV/2A
HV/X
HV/XS
HV1/LC
HV/XLC
Realistic LV-10
Realistic Pro-60

Are there any other Koss HV or related Realistic models ?
I enjoy the sound of the HV/1A. What are the sonic differences between these and the other listed models ?
The HV may use a Mylar transducer rather than a cone driver - can anyone give detail about the transducer used in the HV line ?
Are the Realistic models equal to their Koss counter-partners ? Same 1st quality or were they B-stock, 2nd quality given from Koss to Realistic ? And, which Koss models corresponds to the 2 Realistic models exactly ?
Have seen many HV/1 and HV/1A on used market; were all the various X-types, 1APlus and 2A-type less common or more pricey ?
What is the difference between all the models and types, please ?
Is the only enhancement in the -LC types the addition of the level control pots, or are there other features ?
Specs on any/all models greatly appreciated also.
Love the sound of the HV/1A...are other models really close in sound or are some models vastly different and how ? (ex: bass response, etc).
Have heard Grado developed the SR line from the Koss HV line, not sure if true, any info ?
Thanks for helping.
 
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Won't swear to it but I think Koss makes a set of phones descended from them. I was looking at the Site a while ago for the Pro4AAA and ESP950 and thought I read something.

Also, Koss has a lifetime guarantee on phones made after a date certain. You may want to check and see if yours are under it. If so I understand they will repair, if possible, or replace them for the price of shipping. Not a bad deal at all. Enough to sway me towards Koss phones.
 
Brian said:
Won't swear to it but I think Koss makes a set of phones descended from them. I was looking at the Site a while ago for the Pro4AAA and ESP950 and thought I read something.

Also, Koss has a lifetime guarantee on phones made after a date certain. You may want to check and see if yours are under it. If so I understand they will repair, if possible, or replace them for the price of shipping. Not a bad deal at all. Enough to sway me towards Koss phones.
Click to expand...

Thanks Brian, Great point on the lifetime guarantee. All info much appreciated. Checked thru site and 3 current models seem close, but different. UR55 are High Velocity - not sure what Koss meant, only new one described as that (like vintage labelling). UR40 and KTXPRO1 are also open back. A few models use mylar transducers. Didn't read reviews.
Deciding to stay vintage, and see also Realistic LV-10 is close to Koss HV/1 and Realistic Pro-60 is close to Koss HV/X.
 
BigElCat said:
http://www.audiokarma.org/forums/showthread.php?t=569420

I guess you saw this (?)

Most of my scant information came from HeadFi.com
Click to expand...

Thanks BigElCat, I searched and missed that important thread and, it plus your posts addressed much info - great thread. Of note, it looks like in summary for my goals: - the Realistic counterpart models may either vary a bit in sound from the Koss, or also vary among themselves for the same model (maybe QA/QC issue). I like the series one "original" driver element as in the Koss HV/1 and HV/1A (as I have heard that in my old pair). The LC models are great, but I'm OK if no L and R level controls, and then less (pots) to maintain & clean. The HV/1APlus seem easy to drive. Newer models driver elements in comparative models may not be as good as older models. HV/X looks like it's off my desired list based on impressions from respected listening & construction in that thread. The HV1APlus may attain slightly better bass than HV/1A possibly. Those points, if I'm not mistaken or extrapolating, seem to come from that thread, which is a great thread - Thank You !
 
So, OK, I narrowed what I'm looking for down to all Koss - 3 models (HV/1, HV/1A, HV1APlus) and still wondering about 2 other models (HV/2A, HV/XS). Cut the pack of ten down in half now to five. I want to stay with Koss brand. Here's the 2 I'm still wondering about - Info on the very-elusive Koss HV/2A model is scarce. Wish we could find out more about this model's details. Also, although I ruled out the HV/X, I wonder what the HV/XS differs in details vs the HV/X also.
So, I got it down to HV/1, HV/1A, HV/1APlus, HV/2A and maybe but not likely the HV/XS models. I'm guessing the "1" series all used the original driver mylar element that I like. Is the HV/2A considered the "2" series, or does it still use the same original driver as the "1"'s have ? What is the construction and specs differences between HV/1 - HV/1A - HV/1APlus and HV/2A models ? It may seem the "1"'s all have a very close, similar sound signature. Is the HV/2A way off this signature, just as close , or maybe even an improved early version with some enhancements in sound ? It almost seems there may be a progression among the "1"'s in improvement, maybe or not up to the HV/2A model. The other thread mentioned earlier, points out the step from HV/1A to HV/1APlus may be resulting in a tad bit better bass, possibly. Not sure if the line "progressed" - sonically - by specs - or construction , or just rebadged the model numbers based on grouping years of production ? Finding info is hard - I've been searching the web. Maybe actual Koss sales adds delineate the differences in these model #'s...Koss HV/1, HV/1A, HV/1APlus and HV/2A. Appreciate any help. What are your thoughts ?
 
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Just found out the term "high velocity" for Koss refers to the very large diaphram mylar transducers (rather than cone drivers). Still digging for the rest of posts info.
EDIT : per Koss brochure, in addition,..."velocity type stereophones use acoustically open cushions and earcups, so that the soundwaves from the back of the diaphragm are allowed to travel freely into the open."

describes very early open-back, open, or open-air design as started possibly by Sennheiser H414 in 1968.
 
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Info found online from Koss catalog for Koss HV/1APlus model -
15 to 30,000 Hz frequency response
93 db SPL
140 ohms
0.075% THD (fuzzy to read, but at least 0.095% or lower & much better)
described as handling "digital" music as mentioned in other thread referenced thru posts here; not sure if it has enhanced capability for extreme dynamics and peak bursts or if it was simply a period-era nomenclature for sales, as cd's were becoming popular back then, at that time.

Maybe owner's manuals are circulating for HV1 - HV/1A - HV/2A and HV/XS for more data.
 
Koss customer service responded with specs/info on 4 models - HV/X, HV/2 and HV/1A, and HV/1. The LC versions were the same except addition of the level controls. It appears from literature the HV/1LC was actually the HV/1A with level controls, rather than what would seem to be the HV/1 model version modified. HV/1 started the HV line by itself.

HV/1
decilite driver element defines HV line
acoustically open earcushions and earcups define the HV line, allowing
diaphragm backwaves to travel out to open air

HV/1A
ceramic magnets developed for HV line
decilite driver element
lighter diaphragm total mass
10 audible octaves
15 to 22,000 Hz frequency response
and also 15 to 30,000 Hz per 2 different Koss spec sheets and brochures,
maybe due to different years made or maybe a misprint of literature. It
does appear, however the 30,000 Hz was later production years, as that
brochure also had the HV/X (later model) included on next page.
100 db SPL sensitivity
140 ohms impedence
retail $50 (when made new)

HV/X
variable density earcushions for deep, rich bass
15 to 35,000 frequency response
100 db SPL sensitivity
100 ohms impedence
outer earcup appearance different than other HV models
retail $60

HV2
20 to 20,000 frequency response
0.5% THD
designed to operate with sources having impedences from 3.2 to
600 ohms, for use with portable cassette players or fine home hifi
economically priced

Noted : Koss customer service is excellent to provide this vintage data to us.
 
So, only now looking for any specs, data, details, construction or sound impressions on 2 Final Koss HV-line models.

HV/2A - ? difference from HV/2 ?

HV/XS - ? difference from HV/X ?

Any help, anyone ?
 
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Good work compiling this information!

Thanks for the compliment on my thread. Don't let my opinions 'sway' you too much. I have some degree of hearing loss, and a blown head gasket. :D
 
Just a bit of a recent story on my HV/1A "plus". Do to employment changes I am in the process of relocating to Arkansas and currently staying there with my sister and brother in law. Of course I had to drag some gear along including some headphones and headphone amp. My brother in law has been a professional sound guy in the past and when comparing the HV's to my ATH M50's he said it was hard to explain but the bass in the HV's was full but where it was supposed to be on the stage, back a little. The M50's more in your face. I said exactly, east coast sound KLH model 5 vs west coast JBL L- 100. Imagine that, in a headphone. I guess that's why I prefer the HV's over the M50's. I prefer acoustic suspension speakers over ported speakers unless a sub can be added in. :D
 
Cool. Any idea where I can get one of these drivers? I need a series one, or two from any other series.

Charles.
 
Maybe try Head-Fi site "for sale forum" & place a free wanted add post. Biggest site for finding headphone parts. Or, buy a full headphone from the sale adds there on HF or even ebay for spare parts, but making sure the part you need is fulling working. I bought an extra HV/1A for parts when my original set got real old, and then combined the two sets' parts to make 1 great headphone set.The 2nd "parts" set was only $15 from ebay, shipped free as a parts unit.

Sometimes head-fier's will even offer some parts for free if you just pay shipping, some fellows just want to give the parts to someone who needs them. If you wait long enough searching/checking both HF & ebay, chances are likely eventually your part will show up, unless ultra-rare.

Best bet on HF and D.I.Y.audio sites is to jump on or start a thread for the exact headphone model you have. Then state what parts you need - you will likely get replies from those that have the parts in a bin just sitting around & will send them to you for their minimal price value or a trade of something maybe. If parts are needed on HF, they want to move the thread to "for sale", as it is a wanted parts request. You can make a thread about discusiion there or your model hp may already have a thread - if so, discuss your hp, then ask if anyone has your part, but tell them to PM you, so thread can stay in "discussion" and not moderate over to "for sale". Mods can pull certain posts and move them to the other forum if fitting.

Last chance is to email Koss, they are excellent in customer service, & helped here with their vaulted HV-line archived info that no one else had (nowhere found on www). So, I posted that all here for others. Their parts dept may have your part, but likelihood decreases with age as parts are given out. You would need to contact their technical repair dept. If the part is a Koss-made Radio Shack/Realistic/etc badge the real Koss part will also work in your unit despite badge. If the unit is RS/Realistic - there are fellows around that hoard all their parts, some have a warehouse literally. But you have to find those guys, and best maybe with a RS thread on HF for results, or google. If you find anyone (they are out there) who has a zillion parts, let us know too...there are 1 or 2 real odd-ball RS hifi parts I've never found & would like to have !

Hope of some help, good luck !
 
Also, for all on this thread, since post #11 on Oct 29th, 2014, I did acquire all the models in the Koss HV line.

Thank you to all that helped & again to the fellows here, Brian, BigElCat, & gbroot for their advice, details and other threads with info.

It's been over 2 years, but sorta recall the very 1st original HV, the HV/1 may have been the first hp to achieve 20 to 20, 000 Hz frequency response, a big plus way back then when they were made. Could be wrong on that, it's been awhile, but thought I saw the Koss add stating that when I dug into all the data 2 years back. Believe Koss magazine adds marketted the HV/1 with that attribute.

Plus, we finally got the HV-line specs posted here for historical & reference viewing !
 
I have a working LV-10 and a HV/1 with a buzzing driver. The buzzing driver is actually a 2nd generation driver, with the plastic-welded posts, which is unfortunate. If it was the 1st gen driver I could disassemble it. I believe the problem to be deteriorated cloth between the mylar and the plastic earpiece, as the buzzing only exists on high volume, bass-heavy tracks.

Strangely, the HV/1 sounds much, much better than the LV-10, even though I've done the same upgrades and repairs to them both. (new foam behind the drivers, speaker cloth over the openings in the can, new ear pads)

Charles.
 
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Maybe keep the LV-10 set for use in another room, or as an auxillary set; buy a mint HV/1 set from ebay, and use your current HV/1 for parts extras in future...headband, etc, although you may have only 1 working driver, and as said in your post, not able to pull the good driver out (nor bad driver to replace it).

HV/1 pop up on ebay a few times every year, mint, check completed sales, they go for a reasonable price, if that's your preferred model.

Or, just play your LV-10, they should sound near exact as HV/1, or indistinguishable, and then your HV/1 is still around for future parts...headband, etc.

Not sure if you were going for just 1 set or 2 working sets.

Also, check the linked thread from BigElCat earlier here in this thread, it is excellent, and his restoration work on a similar model may help you if deciding to take a go at repairs. He includes photos to help.

Just some ideas.
 
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