Raal Ribbon Headphones - SRH1A
Dec 1, 2019 at 6:57 PM Post #1,651 of 7,885
I posted the following on another forum about a month ago and I feel like it’s going to be useful for the loud music listeners using amps with more than 100wpc to drive the SR1a. You’re most likely overdriving them...


Fellow Raalers, I’ve been very much enjoying the SR1a and I’ve also concluded that they’re the most resolving and the best headphones I’ve ever heard to date…the details about how I came to that conclusion will be shared on another post. On this post, I would like to share my experience and lessons learned regarding the power requirements for the SR1a.

As most of you are aware, I’ve been driving the SR1a with a single SPL Performer s800 power amp (rated at 185W into 8 ohm / 285W into 4 ohm) and it did a phenomenal job unleashing the dynamics and low end response from the SR1a effortlessly. My normal listening SPL is around 70-85 dBU and I occasionally crank up to a little over 90 dBu for short periods of time. Last night I was listening to a few sub bass and bass heavy tracks such as Starlight by Jai Wold (Goldroom Remix), Exodus by Shai TTokyo Drift by PedroDJDaddy, No Harm is Done (ft Tunji Ige) by Christine and the Queens, Waiting in Vain (Boddhi Satva Afriki Soul Remix) by Groove Cartell, Maya Roze, Flip by Glass Animals… and on my attempt to crank up the volume, I heard both ribbons rattling severely hard with the volume at around 48% and I immediately lowered it.

I’ve reported the “incident” to RAAL-Requisite and both Danny & Aleksandar (the design and lead engineer) immediately got back to me. Below is Aleksandar’s explanation about the effects of too much power on the ribbon excursion levels that could potentially loosen them, thus reducing its longevity:

Well, the amp you’re using has a bit too much power, and the tracks were bass heavy, so when you add those two together, the ribbons will get stretched and start flapping sooner than they used to, that’s all.

Initially, I rated the headphones to 100W/8 Ohm amplifiers, encompassing all kinds of music.

Later on, we extended the rating to up to 150W for listeners of Classical music and acoustical Jazz.

For example, 150W will make the ribbon excursion 22% greater than 100W and 185W will make 36% more excursion than 100W.

With 185W/8 Ohms that you have now, I think it is too optimistic to expect nothing will go wrong with modern production on bass-heavy music.

That kind of music demands a lot of ribbon excursion and overshooting the design goal by 36% is quite a lot for the mechanics of the ribbon.

The trouble is that no matter how briefly it was cranked up, like just a fraction of a second, the ribbons will get overdriven and start loosing the original tension.

Basically, even though the bass on SR1a sounds really nice, they will never be the bass-champs in terms of SPL, so the only thing I can advise is caution with volume knob on such tracks.

I could have designed a built-in safety feature, increasing the acoustical resistance in the vicinity of the ribbon that reduces ribbon excursion when ribbon velocity increases, but in it’s essence, it would be just a dynamic compressor and the sound will become dull and dynamically flat.

So, this sensitivity to excursion, meaning volume and power, is a deliberate choice for the sake of making the dynamics sounds natural as there was no other way to do it.

To me, it’s a no brainer. I’m just cautious with my volume knob and that’s a small price to pay for the sense of unbridled dynamics.

I like my AHB2 a lot, and aside from the sound, I really appreciate it’s clip indicators. They are faster than what I can audibly perceive, but I never let them light up. That’s just an easy way for me to always be on the safe side.

You don’t really need to change the amplifier, but If you could make, or buy, a clip indicator that would be set to trigger at 42Vpeak, you’d always be aware of the power limits that I originally set and the ribbons will last you for a long, long time.

Trust me, I know 200W is a lot of fun, but I couldn’t make the best balance between all the engineering aspects of it, to say that I’m safe over 100W, so if you can live with that, I couldn’t be happier and I hope you will enjoy them for a very long time!”

As you can see, the SPL Performer s800 at full power will overdrive the ribbons causing up to 36% excursion over the design goal (@100W) which is a bit of a stretch and will most likely loosen and potentially damage them regardless of the “exposure time” to such power. My key takeaways to preserve the longevity of the ribbons are to be cautious with the volume knob if you have an amplifier rated above the recommended 100W specially when listening to bass heavy tracks and to add a clip indicator (not sure how to do that as of now) and set it to trigger at 42Vpeak as recommended by Alex so that you’re aware of the power limits that he set to avoid overdriving the SR1a.

That’s all I had…now I’m going back to listen to the SR1a….
 
Dec 1, 2019 at 8:49 PM Post #1,652 of 7,885
Good post, the SR1a's sound is unlike the other phones I own or have auditioned at length and its feeding and care requirements are also different.

I've been playing around with using Schiit's Loki between my Yggdrasil (2) and Ragnarok (1), getting some interesting results. Given the 6 ohm load the interface box presents to the amp I'll make an uneducated guess that the Ragnarok output is maybe 80 watts / channel (?) which is not really enough as I hear it or has been suggested by many for the SR1a. Also given that Loki is SE only it only getshalf the amount of voltage the balanced output on Yggdrasil can provide, forcing me to use a much higher setting on the volume control and I'm not sure whether this has an effect on dynamic range or not.

I hope to be able to order Jotunheim R before year end and hear what it does.

I guess I can start searching for a clipping indicator as well:smile:, just because.
 
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Dec 2, 2019 at 2:08 PM Post #1,653 of 7,885
Someone reported decent result of SR1a driven with Rogue Cronus Magnum
" Rogue Audio Cronus Magnum III ($3k) - Auditioned this. My favorite integrated. Retains the natural sound of the Rogue Audio ST-100. Loses out slightly to the ST-100+RP-7 combo in soundstage. Still a fantastic bargain imo."

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Raal Ribbon Headphones - SRH1A
I'm located in Staten Island, NY which isn't far from Lee's place at all. I appreciate your invite very much, but I only have tunnel vision out of my...



I also have Rogue Cronus fitted with Nos tubes of Telefuken 12ax7 and Mullard 12au7.

Thus I will also try to experiment with it after I am back to my home on January next year.
 
Dec 2, 2019 at 6:40 PM Post #1,654 of 7,885
I got a Topping DX7 Pro today to set up a bedroom system for the SR1a and must say I am pretty impressed what $600 buys from China. Before I get slammed, let me say I have spent plenty domestically over the years! But as a small form factor unit that can sit nicely on a AHB2 it really fits the bill, has all the inputs available as well as all outputs, plus the latest Bluetooth formats, and sounds great. Oh yes, and a remote!
Very interesting to compare my other headphones to the SR1A with just a click on a remote.
B040E5F2-3EF8-4984-ACEB-2393A2BA6E2A.jpeg
 
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Dec 5, 2019 at 10:47 PM Post #1,655 of 7,885
For some strange reason The Drop (formally massdrop) is selling these on their site, but with no discount and no changes. I’m not sure the logic, but I’m curious
 
Dec 5, 2019 at 10:50 PM Post #1,656 of 7,885
For some strange reason The Drop (formally massdrop) is selling these on their site, but with no discount and no changes. I’m not sure the logic, but I’m curious

Look again. $500 discount. Hit the buy button
 
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Dec 6, 2019 at 12:33 PM Post #1,657 of 7,885
I think it means that the SHRA1 is going to be superceded or additions to the line will be made. If they could make a can that was cheaper to make and was still strong 40 Hz - 15 kHz and retail it for $1750 then turn around and make an uber model for $5k, they could nestle the existing one at $2500, until it sells out or the market dries up.
 
Dec 6, 2019 at 8:43 PM Post #1,659 of 7,885
I joined the club. Can anyone recommend any cheap amp that I can use temporarily until I get a new schiit amp?
Another Schiit amp called Vidar! You'll get 90-95% of what the SR1a is capable of...and if you're lucky enough, the Jotunheim R might be released within your return window for the Vidar (assuming that it's going to be released before or around Christmas time), if you go that route.
 
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Dec 7, 2019 at 12:10 AM Post #1,660 of 7,885
I just noticed the this thread is named SRH1A. When the model is SR1A
 
Dec 7, 2019 at 4:41 PM Post #1,662 of 7,885
I joined the club. Can anyone recommend any cheap amp that I can use temporarily until I get a new schiit amp?
Like @MrCypruz said the Schiit Vidar works very well with the SR1a

I currently use two Vidars in dual mono mode with the SR1A which fully powers the SR1A. I’ve also heard the Jotunheim R and will be swapping out the Vidars for it when it releases =)
 
Dec 7, 2019 at 5:28 PM Post #1,663 of 7,885
If you read the very first post of this thread you'll see that the thread starter made a note of the product name change. And yes it would be nice if a moderator would change the name to "SR1A".
Yes needs to be changed so this lengthy thread shows up in searches for SR1a. After all that is what Raal-requisite named it.
 
Dec 8, 2019 at 10:10 AM Post #1,664 of 7,885
BtnrObXh.jpg


Here's a better shot of the size of the impedance matching box. Note that the headphone connection is reversed from the usual XLR connection: the male XLR is on the box instead of the headphone cable. Good move, since mistakenly plugging the headphones into a headphone amp could very well damage the amp, and this connector makes that physically impossible.


Can you drive these RAAL using just the Nagra DAC?
nevermind, just researched....

But, has anyone measured the milligauss readings between the cups? Say at 80 - 90 db SPL?
Thanks.
 
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Dec 9, 2019 at 12:23 PM Post #1,665 of 7,885
Can you drive these RAAL using just the Nagra DAC?
nevermind, just researched....

But, has anyone measured the milligauss readings between the cups? Say at 80 - 90 db SPL?
Thanks.

What's the specific EMF concern? Can't imagine it would be more than Stax between the cups.
 

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