Latest Thread Images

Helot 2x OTL - By Spartan Music
Mar 23, 2023 at 6:56 PM Thread Starter Post #1 of 52
D

DropTekRoon

100+ Head-Fier
Joined
Dec 28, 2022
Posts
119
Likes
291
Location
US
helot-2x-headphone-tube-amp-1_720x.jpg
helot-2x-headphone-tube-amp-2_900x.jpg


https://spartanmusic.co.uk/products/helot-2x-headphone-tube-amp

The Helot 2x is unfortunately only sold in Europe, so it is limited to a certain amount of people. There also seems to be a clone of the amp that's called the Wangs PHA-T1.

There are not a lot of specs at all for the Helot or a lot of information in general other than a handful of reviews. That gave me the idea of starting a thread so that others can also share their experiences with this amp as well as tube rolling or any questions.

I was curious about the tube rolling possibilities for this amp. When purchasing the amp, you get the choice between JJ Electronic tubes or Electro Harmonix tubes. The Helot uses a 12bh7 and 12au7/Ecc82 tube. The 12bh7 is more related to the transformer and is mainly used to lower the output impedance to run headphones from 32-600ohms. It still does have some an impact on the sound, but the 12au7 tube will have more of an impact on the sound.

Screenshot_20230313_105802_Gmail.jpg


If you look at pins 4, 5, and 9 on the PCB picture posted above, they all go up to where it says 6.35. This is the heater that the Helot uses. Since the Helot uses 6.3v heaters, this opens up the possibility of rolling 6sn7 tube variations in place of the 12au7 tube if you wanted to do so.

Specs:
Headphone impedance: 32-600ohm
Frequency response: 20Hz-30kHz
THD (Total harmonic distortion): 95dB
 
Last edited:
Mar 23, 2023 at 7:50 PM Post #3 of 52
Post an update after you give it a listen. I still need to do some more listening with a Tung Sol 6sn7 tube with the amp. The Wangs looks like a rebranded version of the Helot. The specs are identical and the only difference seems to be the color of the amp and the fact that it is sold in the US.
 
Mar 24, 2023 at 5:30 PM Post #4 of 52
Stock Electro-Harmonix vs Brimar Cv4003wa...

Right out of the box, the Nos Brimar was much more agreeable.
Open and sweet in the midrange, lovely detail too.

The EHX just sounded muddy and distorted in the bass with both Focal Clear and CustomCanz modded HD650.
Maybe I need to burn in the tube more, or I have a subpar one...
 
Mar 24, 2023 at 6:08 PM Post #6 of 52
DropTekRoon said:
Post an update after you give it a listen. I still need to do some more listening with a Tung Sol 6sn7 tube with the amp. The Wangs looks like a rebranded version of the Helot. The specs are identical and the only difference seems to be the color of the amp and the fact that it is sold in the US.
Click to expand...
Voltage difference? 🤔
 
Mar 24, 2023 at 6:16 PM Post #7 of 52
I have the Electro Harmonix with mine. Unfortunately, the 12au7 tube didn't work when I got it. I'm assuming that air somehow got into the tube during the shipping process. It glows purple for a few seconds when I turn on the amp and then it doesn't light up anymore. No audio also. I was using a vintage Sylvania 12au7 I had to replace it.

Currently, I have a Tung Sol 6sn7 with the Electro Hormonix 12bh7 in the amp. I'll post some impressions when I do some more listening

jonathan c said:
Voltage difference? 🤔
Click to expand...
Hmm I wouldn't think so. I would assume that the Wangs also runs a 6.3v heater.

From some of the power specs I saw on the Wangs, it puts out 1000MW into 250ohms and 500MW into 600ohms. The specs are identical to the Helot. Since the Wangs ships to the US, it would be a good option if someone were curious about wanting to try out the Helot. Looks like the Wangs is out of stock everywhere though.
 
Last edited:
Mar 24, 2023 at 6:34 PM Post #10 of 52
WorksUnit said:
Interesting, I used too quite happily run the Electro Hamonix in my old Helot. This time around though is not positive.
Click to expand...
How noticeable was the difference when using the Brimar Cv4003wa compared to the Electro Harmonix? I kinda wish I got to try the Electro Harmonix 12au7 tube, but I had extra tubes I could use with the amp, it wasn't too big of a deal.
 
Mar 24, 2023 at 6:55 PM Post #12 of 52
I've heard some pretty good things about the EH 12au7 actually. The Gold Lion would be a fun tube to try out in the amp. That might be the next 12au7 tube I get. I'll post some impressions here in a bit on the Tung Sol 6sn7 tube with the amp.
 
Mar 25, 2023 at 10:59 AM Post #15 of 52
Alright, so the Tung Sol 6sn7GTB is a pretty solid tube. The low end is what this tube does best. It delivers a nice punch. It has somewhat of a brighter midrange. Good extension on highs. I find it to be really good with acoustics/vocals.

Only bad thing is that it seems kinda noisy when using it with lower impedance headphones at times. I start to get a slight audible hum close to half volume. It isn't bad though and it isn't noticeable when audio is playing. The somewhat annoying part is the crinkling like sound which is present a lot time no matter how low I have the volume. Not audible when audio is playing though. A tube damper could possibly help with this. It's also possible that this specific tube is just somewhat noisy with lower impedance headphones.

When I used the same tube on the Vali 2 with the same pair of headphones, I remember that I had the same hum/crinkling sound so it seems more than likely that it's just the tube and how it works with lower impedance headphones. But overall, any noise from the tube isn't a big problem since you can't hear it when audio is playing so it doesn't bother me too much. There are times when it's quiet.

I didn't get any audible hum/noise with the 12au7 Sylvania tube until I really turned up the volume, but it's not a problem since that would be way too loud anyway.
 
Last edited:
You must log in or register to reply here.

Users who are viewing this thread

Total: 2 (members: 0, guests: 2)
Back
Top