[yyzSB]

Before any of the direct drive amplification solutions were even a thing, I had the AHB2 driving the SR1a. It had enough power to drive them with authority but it sounded lifeless, flat, clinical and was ultimately returned. o my ears, a Schiit Vidar power amp did a better a job than the AHB2, and even better in dual monoblock configuration. I ultimately settled with a SPL Performer s800 power amplifier.

Then the JotR was released, I liked it for the form factor and its ability to drive the SR1a with grunt and control for such a tiny box...but it still wasn’t better than the Performer s800 power amp. The JotR sounded thin, shouty and harsh in comparison. Fast forward a few months and the HSA-1a was released, it was a massive improvement over the JotR driving the SR1a but the conventional headphone output was mediocre. The traits of the HSA-1a when compared to the JotR can be summarized as a much better treble presentation - a lot less harsh but you could replicate that at loud volumes, improved clarity, expanded soundstage, better bass definition.

RAAL-requisite went back to the drawing board and the HSA-1b became a reality, mostly based on the feedback from early adopters of the HSA-1a. The HSA-1b is the HSA-1a on steroids, it does everything better, the most noticeable improvement being the conventional headphones output.

So the short version of my answer to your question is, based on my experience and my preference, the HSA-1b will do a better job highlighting the strengths of the SR1a and will drive them to levels that I don’t believe the AHB2 would be able to.

Thanks that is some great feedback. Your description of the AHB2 is also how some people feel it sounds with 2 channel speakers (they do not like it). However, for me I love it with my Thiel CS3.7 and previously my KEF LS50's. I also love my Meze Empy with my HPA4 whose amp section sounds exactly like the AHB2.

I am going to get 1 or 2 new DACs soon and that will have a huge impact on my system because the current gear is basically just neutral. I am hoping to get a Halo May KTE and the AudioByte VoX | ZAP | HUB. Spice things up a bit.

 

[paradoxper]

It would be very important to me if the 2 channel amps can drive these headphones to their best ability (or near the best). I see it as a selling point for my background in mostly 2 channel.

I have 2 AHB2's and want to have a listen to the SR1a soon. The local distributer (Danny?) is close by to me so I hope I can manage to get a demo. COVID makes these things difficult.

You'll likely find level playing fields between AHB2's and HSA-1b -- though more similar to Jot R until you step up to real space heaters for amplification.

 

[Shahrose]

Funny you should ask...Raal/requisite have a new silver cable coming out shortly as an upgrade. I've been listening to it for the past week or so and I absolutely love it! It's opened up the sound staging and transparency over the stock cable and when coupled with the HSA-1b + Chord DAVE, personal audio just doesn't get any better to my ears. MSRP will be $1050 USD and it is beautifully constructed and sounds sublime! I will be covering this entire setup (including the cable) in my upcoming HSA-1b review.

Coincidence, had been talking to Moon Audio the last few weeks regarding a custom silver cable for the SR1a. All of my cans are rewired with silver which I almost always find to be superior to other conductors. Not saying it'll be better for the RAAL, but I'm almost certain I'll prefer it to the Black Dragon, which is a sidegrade from the stock wire.

Will be on the lookout for your full impressions.

 

[yyzSB]

You'll likely find level playing fields between AHB2's and HSA-1b -- though more similar to Jot R until you step up to real space heaters for amplification.

Not sure if I follow the space heater comment. Are you saying a Class A amp or a much more powerful amp (usually not a space heater)?

 

[paradoxper]

Not sure if I follow the space heater comment. Are you saying a Class A amp or a much more powerful amp (usually not a space heater)?

It was more-so referencing the scaling of the interface out of big boy amps so to speak.

 

[jlbrach]

I would love to hear appreciably better than the hsa-1b, that would be incredible...truth is the beauty of the hsa-1b is the ability to forgo a speaker amp and all that goes along with it for a really good amp both with the sr1a and traditional HP's.....

 

[yyzSB]

Actually the AHB2 is in the big leagues when it come to amps. The price fools people thinking it is not upper level and also the lack of distortion and noise also make people dislike the sound. Most people are not used to the absence of distortion and noise in the amps. I got this exact feedback from the brother of my speaker designer. He founded the speaker company with the speaker designer. He was commenting that the AHB2 sounds so different but he is now thinking this is the way it should sound.

I was deciding between the Luxman m900u and the CODA #16 or #8 and the AHB2. Once I got the AHB2 I eventually ended up with an all Benchmark stack. Though I am stiill considering the other 2 amps for a future living room system.

This is the latest review of the BM stack from a very snobby audio rag.
https://www.theabsolutesound.com/articles/benchmark-media-systems-la4-line-amplifier-and-dac3-b-dac

*********************
I just got an email from RAAL. I will be able to have a demo the SR1a next month (likely 2 weeks from now).

 

[paradoxper]

I would love to hear appreciably better than the hsa-1b, that would be incredible...truth is the beauty of the hsa-1b is the ability to forgo a speaker amp and all that goes along with it for a really good amp both with the sr1a and traditional HP's.....

That's the inconvenient truth. It's partially why I think Kevin Gilmores uberamp2 will be just the ticket. If you are going to drive the SR1a out of hundreds of pounds of monoblock to get the best out of them, you might as well simply listen to speakers.

 

[MrCypruz]

It's partially why I think Kevin Gilmores uberamp2 will be just the ticket.

When is this amp going to be widely available for purchase? Would love to get one to compare against the HSA-1b... I hope they deliver something special.

 

[paradoxper]

When is this amp going to be widely available for purchase? Would love to get one to compare against the HSA-1b... I hope they deliver something special.

Find a friend on Head-Case and start a commission. Otherwise I'm afraid his designs aren't commercial.

 

[MrCypruz]

Find a friend on Head-Case and start a commission. Otherwise I'm afraid his designs aren't commercial.

Ah it’s one of those niche products...will see if I can find the time to commit to such project. Thanks for letting me know.
I’ve only dealt with Birgir on Head-Case...time to search for my credentials to access my account there.

 

[paradoxper]

Ah it’s one of those niche products...will see if I can find the time to commit to such project. Thanks for letting me know.
I’ve only dealt with Birgir on Head-Case...time to search for my credentials to access my account there.

I'd bug Justin with a petition to start an uberamp.

 

[Duncan_McCloud]

Apologies if this has been done before, but could someone share their eq settings for the Raal?

I found one by Amir at ASR forum, screenshot as follows:



I tried it out but I didn't quite like the low end; bass notes ended up sounding like a soft thick snare drum. Sounded too distorted for my liking. The higher frequencies were OK.

I understand there are a lot of variables with the Raal, ie angle of the wings, placement and positioning and how it affects the overall FR. I prefer the wings angled out in such a way they just miss touching my ears; this has the best mids and bass for me. Angled farther outwards makes the highs more pleasant, but then it sounds a bit too thinned out.

I watched the YouTube video by Raal that shows how to set up the frame. Seems there is more to do with the Raal than the TC lol!

Tested this EQ last week. Same feelings about the bass. Too "boomy" and distorted. Need to focus more on the High filters, which may adjust a little bit the harshness which sometimes happens

 

[Roasty]

Tested this EQ last week. Same feelings about the bass. Too "boomy" and distorted. Need to focus more on the High filters, which may adjust a little bit the harshness which sometimes happens

Yes, really distorted. I'm surprised he came up with that EQ and posted it.. Because it really doesn't work well. I even tried it with varying wing positions and all didn't sound good.

 

[simorag]

Apologies if this has been done before, but could someone share their eq settings for the Raal?

I experimented several settings, and in general I have been impressed about how well the SR1a responds to EQ with respect to the other heapdhones I have tried, where ANY form of EQ resulted in a perceived loss of transparency negating the benefit of the EQ altogether to my ears.

At a certain point, I read the post from Alexandar R., where he provides a simple guidance to warm-up the overall tonal balance of the SR1a towards a more euphonic signature.

Below you find (taken from the original post linked above), the RAAL resistor box de-emphasis diagram in its original and modded ("euphonic") form:

The difference between the two curves (i.e. the corresponding EQ) is as below:

My go-to personal curve is similar to this one, where a further increase is added in the sub-bass region, plus a -3dB/Q=2.5 dip around 7kHz, an area where I am subjectively quite sensitive.

Of course, a headroom adjustment of -6dB must be applied to this whole curve, otherwise severe distortion or digital clipping will occur very often due to the low frequency elevation.