[Torq]

Sucks the HSA-1a doesn't have a pre-in option like the Jot R does, so no tube preamp can be used with it.

What are you talking about?*

The HSA-1a has two analog inputs, just like the Jotunheim R, one single-ended (RCA) and one balanced (XLR). The Jotunheim R has an option for a DAC on top of that, but both of the units are primarily analog-in

There's no issue at all putting a tube-buffer or tube-pre-amp in front of it, just like you'd do with a Jotunheim R if that's what you wanted. As with ALL such arrangements, you just need to make sure your tube-pre/buffer has an output level that doesn't clip the inputs on the amplifier it is feeding.

---
*Unless you're being sarcastic and I missed it being pre-coffee.

 

[rkw]

Sucks the HSA-1a doesn't have a pre-in option like the Jot R does, so no tube preamp can be used with it.

Jot R has a pre-out switch. Not pre-in.

 

[Thenewguy007]

I could have sworn I saw it did.

 

[tunes]

I just found my answer;

https://raalrequisite.com/amplifiers/hsa-1a/

Any reviews yet comparing to the JOTR?

 

[FLTWS]

I'm not aware of any. And it takes some time to do a proper one.

 

[thomaskong78]

I'm not aware of any. And it takes some time to do a proper one.

Had you ever tried Rh5 pre in front of Jot R?

 

[tunes]

With such a high level system and Jot-R designed for the SR1a this bass clipping really needs to be addressed or many will not want to consider buying this over a STAX system with clean non-clipping bass response.

Just got my SR1a JOTR SYSTEM. Waited a few days for the COVID to die. Now I want to hook it up to my CHORD DAVE HMS. Can anyone tell
me how to connect the two to avoid clipping with the preamp feeding the DAVE? Is volume on JOTR on highest or lowest level with volume control through DAVE remote? Thanks

 

[exdmd]

Any reviews yet comparing to the JOTR?

Nope when there is one you will probably see it here first by Torq at the HSA-1a thread.

 

[thomaskong78]

Just got my SR1a JOTR SYSTEM. Waited a few days for the COVID to die. Now I want to hook it up to my CHORD DAVE HMS. Can anyone tell
me how to connect the two to avoid clipping with the preamp feeding the DAVE? Is volume on JOTR on highest or lowest level with volume control through DAVE remote? Thanks

I also use Dave and HMS. With maximum volume on Jot R, I usually use -20 or so.

If you turn down the volume on Jot R, you may have Dave around -10.

 

[FLTWS]

Had you ever tried Rh5 pre in front of Jot R?

No. I believe the simplest, shortest, chain is the most transparent sound of the source material.

 

[tunes]

I also use Dave and HMS. With maximum volume on Jot R, I usually use -20 or so.

If you turn down the volume on Jot R, you may have Dave around -10.

I also need to know what cables and to which input on DAVE I connect the JOTR to??

ty

 

[thomaskong78]

No. I believe the simplest, shortest, chain is the most transparent sound of the source material.

I usually agree with your point.

For 10 years I had used passive attenuator in front of Krell KSA 150 to get the most transparent sound.

But Sr1a driven by JotR go above the limit with too much transparency close to aggressiveness.

I had tried
Nobsound NS-08E
https://www.soundandvision.com/content/tube-amps-pocket-change-nobsound-ns-08e
fitted with Nos RTC 5654 RT tube in front of Jot R to get more relaxed and musical voice of Eva Cassidy.

The above Nobsound NS 08E also works well with HD 800s.

 

[thomaskong78]

I also need to know what cables and to which input on DAVE I connect the JOTR to??

ty

I use 20 ft balanced cable made by Purist Audio Design.

 

[Torq]

Nope when there is one you will probably see it here first by Torq at the HSA-1a thread.

I've got five solid days of listening via the HSA-1a so far, with some of that time spent doing some on/off comparisons with the Jotunheim R (and a little vs. other amps using the interface box). And as part of that I have most of the non-performance-related elements of a review written (operation, specs, features/functions etc.), I figured I'd have the rest of the listening done, and that written up late next week ...

... but there's an interesting development with the HSA-1a which will delay my full review a little. Though I think that delay will be well worth it, since the "new development" is:

• The HSA-1a has been updated to swap the 2nd headphone output for a conventional balanced headphone output, so that it can be used both to drive the SR1a and also any normal headphone (i.e. not electrostatic) cans as well (using a standard balanced cable for the appropriate headphone model.
• For super-hard to drive headphones, like the HE6(SE) and Susvara, there will also be an adapter cable in the box to allow it to power those properly.

So this turns the HSA-1a into an amplifier that can drive the SR1a, any normal headphone, pathologically hard-drive headphones AND speakers - all from one box.

I will be getting an updated unit in short order (likely this week), and will be holding off on my full review until I can put that through it's paces, including evaluating the standard headphone output with my usual array of flagship headphones.

Finally, as I understand things, anyone that already ordered/received an HSA-1a already will get, or be able to get, the updated unit for no charge (if you need to return a unit for the update, shipping will be covered)!

 

[FLTWS]

I wonder if they will keep the dual ribbon drive amp for pro use?
I guess the switch to control Earfield Ribbon Monitors / Circum-aural Ribbons (probably a different or no frequency contouring needed), should still apply to the HSA-1's male HP XLR connection.
This new unit is really multi-use for me now.
Hopefully they keep the nice red volume knob and volume level markings making it easier to repeat level settings (and On/Off switch on the front!).
I wonder how many watts the amp delivers into the ribbons (nominal?) 0.4 ohm load? As well as regular HP drivers of nominal impedance's from say 30 to 300 ohms?
Questions, questions, LOL! In due time.
Interesting how soon after intial release of the double ribbon driver amp model they came up with an even more appealing version. I'm ready for this.