I was rummaging through some boxes at home and came across a pair of Ross RE-270 headphones I last used maybe 35 or more years ago. I seem to recall they were quite good at the time but needed the right amplifier to do justice to them; otherwise they were not very loud.
Does anyone know what is the input spec for those headphones? Impedance, power, etc.? Are they transformer-inputs? Does anyone have a spec sheet they could scan?
What is the best way to drive them?
Like I say, it's 35, maybe 40 years, since I last used them and had a suitable amp for them. I'm curious to see how they've survived and whether my memory of the sound quality is correct. The amps I now have at home don't have headphone sockets; plugging them into a Samsung tablet, the sound is not loud but seems very clear throughout the frequency range.
Does anyone know what is the input spec for those headphones? Impedance, power, etc.? Are they transformer-inputs? Does anyone have a spec sheet they could scan?
What is the best way to drive them?
Like I say, it's 35, maybe 40 years, since I last used them and had a suitable amp for them. I'm curious to see how they've survived and whether my memory of the sound quality is correct. The amps I now have at home don't have headphone sockets; plugging them into a Samsung tablet, the sound is not loud but seems very clear throughout the frequency range.
I happen to have Hi-Choice book on headphones ( two editions ) the older one includes Ross RE272 which didn't get a recommendation or best buy- sorry wasn't highly thought of, the previous RE258 did get recommended.
To be fair its in competition with Stax and other quality headphones like Sennheiser --its cost was £37 --up to 5K its reasonably flat BUT------.
Impedance is 56 ohms use with 330 ohm resistor via jack - goes loud ( but so does the distortion) frequency response graph doesn't look good at higher frequencies --Ross Electronics London W1 .
To be fair its in competition with Stax and other quality headphones like Sennheiser --its cost was £37 --up to 5K its reasonably flat BUT------.
Impedance is 56 ohms use with 330 ohm resistor via jack - goes loud ( but so does the distortion) frequency response graph doesn't look good at higher frequencies --Ross Electronics London W1 .
You could try to find a copy of the (article in) "Hi-Fi News & Record Review" of March 1977: The "Too good for the price" list - #40 by LeDechaine - Headphone Discussion / Help - HifiGuides Forums
Taken from the book -
"on audition the 272,s rated a little below average .The overall balance was not particularly inaccurate but fine detail was noticeably muddled .The mid-band was slightly boxy and shut in,with a grainy and aggressive treble which proved somewhat fatiguing , this is not a good show at the price .
Sensitivity for 2./83V( via 330 ohms for jack ) at 500Hz(equivalent to 1W/8 ohms) ---100dB lin/100dBA.
"on audition the 272,s rated a little below average .The overall balance was not particularly inaccurate but fine detail was noticeably muddled .The mid-band was slightly boxy and shut in,with a grainy and aggressive treble which proved somewhat fatiguing , this is not a good show at the price .
Sensitivity for 2./83V( via 330 ohms for jack ) at 500Hz(equivalent to 1W/8 ohms) ---100dB lin/100dBA.
The Ross RE-270 are actually not a "cheap Korean copy of a Japanese design(s)"; they were marked Made in Japan and, I seem to recall, were intended to be Ross's premium model. Unfortunately it was not an unqualified success, being difficult to drive and not loud unless driven properly.
Listening again to the RE-270, it doesn't do loud on normal headphone outlets; it needs a higher voltage signal, probably a direct speaker feed. The DC input impedance on the RE-270 measures at about 16 Ohms; I think it is a transformer-coupled input driving directly onto the electrostatic (electret) elements. I remember now that there was a question at the time whether an electret design with transformer input could ever have enough voltage on the elements to go as loud as conventional high voltage electrostatic designs like Stax, never minding quality comparisons.
Out of curiosity I measured the DC input impedance on some other, conventional headphones that I had easily to hand:
All of the Sennheisers happily do loud even on my mobile phone.
Listening again to the RE-270, it doesn't do loud on normal headphone outlets; it needs a higher voltage signal, probably a direct speaker feed. The DC input impedance on the RE-270 measures at about 16 Ohms; I think it is a transformer-coupled input driving directly onto the electrostatic (electret) elements. I remember now that there was a question at the time whether an electret design with transformer input could ever have enough voltage on the elements to go as loud as conventional high voltage electrostatic designs like Stax, never minding quality comparisons.
Out of curiosity I measured the DC input impedance on some other, conventional headphones that I had easily to hand:
- Sennheiser HD 420 600 Ohms - these are almost as old as the Ross RE-270; much abused and have lost their ear cushions
- Sennheiser HD 590 100 Ohms - I liked these better than the original HD 600 for classical music; still the most comfortable for long listening/editing sessions.
- Sennheiser HD 660S 150 Ohms
All of the Sennheisers happily do loud even on my mobile phone.
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You might have a point ,although "Big Finance" now owns the Ross Group they were originally listed as Ross Electronics London W1 but did import from Japan---not everything out of Japan was exceptional in audio reproduction and most of those Japanese companies are either owned or have factories in China .
Who do you think owns Stax now ?
Who do you think owns Stax now ?
Oh I do understand what you are saying. And indeed, back in the day when I bought the RE-270s, Ross Electronics was still a British company.
Ross's products were never top tier; not even equal to similarly priced Sennheisers. But the RE-270 was touted in the reviews at the time as being something special and at an attractive price. That was a long time ago and any of the companies from that era that have survived have probably changed hands several times.
What could more epitomise British hi-fi than Quad, Wharhedale, Mission, Leak, Castle, or Audiolab? All now are brands of IAG in China.
I plugged the RE-270s into an Edirol UA-101 this evening, for a music session. To test the setup, I tried the RE-270s. With the volume control at a normal position I could hear nothing at all. With the volume cranked up to the max the sound was still not loud enough, but the sound quality, particularly at the top end, was beautiful. I listened to Tallis' Spem in Alium Nunquam Habui sung by the Taverner Choir; it was magically clear. Then I switched back to the Sennheisers for the business of the music rehearsal.
Ross's products were never top tier; not even equal to similarly priced Sennheisers. But the RE-270 was touted in the reviews at the time as being something special and at an attractive price. That was a long time ago and any of the companies from that era that have survived have probably changed hands several times.
What could more epitomise British hi-fi than Quad, Wharhedale, Mission, Leak, Castle, or Audiolab? All now are brands of IAG in China.
I plugged the RE-270s into an Edirol UA-101 this evening, for a music session. To test the setup, I tried the RE-270s. With the volume control at a normal position I could hear nothing at all. With the volume cranked up to the max the sound was still not loud enough, but the sound quality, particularly at the top end, was beautiful. I listened to Tallis' Spem in Alium Nunquam Habui sung by the Taverner Choir; it was magically clear. Then I switched back to the Sennheisers for the business of the music rehearsal.
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