[Slipmyster]

If you want to explore Brimar, you are in the right country

I've been reading that the one's made in England are very good but I can't find much on the foreign versions and there seems to be a big difference in price between the two versions. The 12au7 is reasonable but the 12bh7 made in England gets quite expensive.

Martin

 

[Slipmyster]

Just thought I would share som pic's of my Helot with tube raiser's under the 12bh7. Hoping it will help with cooling a little and I think it also looks the part.

Also tube's I have so far. The JJ tube's came in my amp. I'm currently using the EH 12bh7 with a Sylvania 12au7 black plate square getter up front. The 12 bh7bon the end is a Chinese tube I tried because they were cheep. Not a good match for the Helot it's a bit muted and has to much bass. Would make a goot tube for a bass guitar amp though.

 

[andjar]

I've been the pretty happy owner of a Spartan Helot2X for a few weeks now.

I've only changed the stock 12au7 with a Brimar one. The original(russian/ehx rebranded)didn't sound very good ,the midrange was kind of thick nontransparent compared to the very clean spacious signal coming from my topping dx3+ pro.
The Brimar sounds much better, the midrange depth and transparency was great. The only downside was some bass distortion perceivable only with my planar Hifiman HE1000 Stealth. But all my dynamic driver cans sound great throughout the range.

Compared to the hybrid Schiit Vali 2++ ,the tube rolling is generally more audible for the better or for the worse . Using my Topping dx3+ as a dac and preamp for both,the Helot is also much more powerful than the Vali managing to drive my (hardest to drive by far) 250Ohms Beyerdynamic DT990 pro much louder. Also the dx3+ pro + Helot stack is significantly more powerful than the Topping on its own.
For planar headphones i would still recommend a hybrid like the Vali or a digital-SS amp instead.

The Spartan Helot 2x is a great sounding, class A ,pure tube amp for a crazy good price.
Here is s goodie for you, a gutshot of the Helot showing how well designed and made it is. No pcb mounted resistors,no ss chips, just nice big beefy capacitors and resistors .

 

[Grom]

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.



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

Where should I attach the ground wire to this?

 

[WorksUnit]

^No binding post^.
Clocked many a happy hour without a ground...

 

[reg66]

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.

Just placed an order for a Spartan, pretty excited for an inexpensive tube amp! Curious as to which 6SN7 adapter you went with? The ones I'm looking at I'm skeptical they'll fit in the chassis/case hole... Or will/do they fit fine? I'm looking at ones from Aliexpress or ebay.

Got quite a number of decent 6SN7's that I can try up it, happy days!

 

[reg66]

Just thought I would share som pic's of my Helot with tube raiser's under the 12bh7. Hoping it will help with cooling a little and I think it also looks the part.

Which tube raiser did you use bud? Do you have to dismantle the amp from the case to put it in place? The ones I've seen have a kinda flange around the edge that i think will be too wide to fit directly in the case hole (unless i just grind the flanges down!)

 

[reg66]

Anyone looking here for reviews on this wee amp, as I was a short while ago, here's a few snippets from Amazon reviews;

'My equipment is Tidal (hifi) from Imac to RMA ADI-2 DAC, headphones are Drop HD58X, Drop HD 6XX and Bowers and Wilkins p9.
I also own a Little Dot MK1 and MK2
I have invested significantly in both my Little Dot amps, upgraded the valves, op amps and mains cables and they sound great but they needed significant investment to get them to where they are now.
The difference with this amp is that it sounds as good if not better straight out of the box, no extra cash needed!'

'This sounds amazing . I had a couple of Little Bear "tube amps" and they don't come close to this . There is no background noise at all , not even a max volume ....is dead silence . If you have some hd600 range headphones you will like this . I have some HD565 Ovation bought 20 years ago and they sound amazing on the tube amp .
And to receive an tube amp with good tubes out of the box , you won't find to many of this . The tubes alone are 30 pounds if you want them'

'For hi fi use, it definitely ‘softens the harsh edges’. Used with a pair of Sennheiser HD650’s and a Quad Vena amp (using Tidal via Bluetooth as a digital source), it increased the depth of the music. This is a very clean but musical setup and the headphone amp seemed to give it increased dynamics.' And 'I have also used it with a direct source from my iPhone and this seems to be where it really shines. In my opinion, Tidal with its hifi mode is noticeably more ‘3D’ than Spotify and adding the amp gives another jump in quality. It’s almost impossible to describe sound in words as it’s so subjective, but the headphone amp seemed to make the source sound more live - reverbs were more noticeable and vocals definitely felt more real. To my ears, the difference seems to be in the midrange which is where I think some headphones can be a bit weak. The amp gave me a sound with the iphone that was fairly close to the Quad Vena, which is pretty amazing considering the cost difference!'


I'm happy to write a wee review myself when it arrives, got a number of 6SN7's to try and a few 12AU7 + 12BH7 on the way (I'll list em later). Unfortunately i don't have another tube amp to compare to but have owned Lyr 3, xDuoo MT 602 and Tor Audio Nick tube amps. I downsized and only have one pair of 'phones to review on - Focal Clear MG Pro. For DAC I'll be using NJC Audio reference DAC, so the only 'colour' etc will be that of the Helot. I'll be comparing it with the matching NJC Audio reference amp (another great maker of handmade reference equipment - well 2 men that I know of - that deserves more recognition. A lot of bang for you buck, but still a fair whack more than this little tube amp). I digress. Looking forward to getting this wee tube amp. I do have another tube amp in mind to purchase when funds afford, but that won't be any time soon. So here I am on a shoe string and quietly excited to get back on the tube wagon!

 

[Slipmyster]

Which tube raiser did you use bud? Do you have to dismantle the amp from the case to put it in place? The ones I've seen have a kinda flange around the edge that i think will be too wide to fit directly in the case hole (unless i just grind the flanges down!)

It was a inexpensive bakelite gold pin one. It went in easy but I'm not sure how easy it will be to take out if I ever need to remove it but it definitely helps to cool it down lifting the back tube out of the case.

 

[reg66]

It was a inexpensive bakelite gold pin one. It went in easy but I'm not sure how easy it will be to take out if I ever need to remove it but it definitely helps to cool it down lifting the back tube out of the case.

Did you raise it up just a little with something like this;

Or did you raise all the way with a socket saver like this;

Cheers dude

 

[Slipmyster]

Did you raise it up just a little with something like this;

Or did you raise all the way with a socket saver like this;

Cheers dude

All the way with a socket saver I'd recommend replacing the power cable as well if possible. I use Russ Andrews power cords in my headphone system. I know some people say they make no difference but I think if you can use a better quality cable it can't hurt.

 

[andjar]

Do you guys know where i could get a 12BH7 socket saver/tube raiser from?
Is the pin layout the same as for 12AX7/ECC83?

 

[OctavianH]

Do you guys know where i could get a 12BH7 socket saver/tube raiser from?
Is the pin layout the same as for 12AX7/ECC83?

There is a forum member @Deyan who makes custom adapters. I am sure he can help you with a socket saver or what you need. PM him.

 

[reg66]

Do you guys know where i could get a 12BH7 socket saver/tube raiser from?
Is the pin layout the same as for 12AX7/ECC83?

12BH7 has the same 9 pin layout as 12AU7/12AX7 etc. As the socket saver just passes through pin for pin I'm guessing yeahh, it's the same. I'll order one and let you know, though it might be a while as ordering from China. Gonna order the gold pin one from here

 

[Slipmyster]

12BH7 has the same 9 pin layout as 12AU7/12AX7 etc. As the socket saver just passes through pin for pin I'm guessing yeahh, it's the same. I'll order one and let you know, though it might be a while as ordering from China. Gonna order the gold pin one from here

I ordered mine from eBay but was lucky I found a couple in the UK. I'm pretty sure Amazon have them as well.