Upgrade your system with a 6j1 Tube Buffer for €20

I thought I would share with other users a really good cheap upgrade you can add to any system. It improves stereo separation, soundstage, bass amongst other things.
It is called a Tube buffer. It improves the signal and sound level. Possibly detail in some systems.

Some of them have a volume control and can be used as a preamp but they can be inserted into any system. The best thing is they only cost around £20. That’s not a typo, yes a tube preamp for £20!

There are many different vendors. I can reccomend the FX Audio Tube 01 which probably is the best built with the nicest best case. You can buy it as a diy kit for about half the price. It runs on 12v so pretty safe.

People then get in to upgrading the power supply and tubes to go even further.
They are based on the X10 tube buffer from Musical Fideliry that was popular years ago.

A great way to get into the valve sound for a small investment, you may also find the tubes smooth out a harsh system.
They are available on ebay and many other places, search for ‘tube buffer’ or ‘6j1’ which is the name of the valve most use.

Dont be put off by the very low price, it can improve even expensive high-end systems.
My system is Volumio, RPi2, ES9038Q2M DAC hat (again from ebay, highly recommended), FX Audio Tube 01 (the buffer) and Harbeth DPM1 active speakers. I am biased of course but It sounds just incredible.

I’m curious if anyone else has one and what they think. Or if you do buy one and try it let me know.

You know. I successfully detoxed from tubes, years ago.
Now I read your post and I am tube-sick again.
Dont’ know whether to say thank you or shame on you eheheh

I am getting it now :wink:

I’ve been using one for the last 18 months or so, in front of a variety of TPA3116 based amps, and have gone through a linear PSU upgrade and various tubes.

For the initial outlay, I’d recommend it, but beware the upgrade path and tube rolling can get expensive…

There’s a whole lot of info and experiences here:


Well I am absolutely honoured to get a reply back from ‘the man himself’.

I know what you mean about tubes, the sound could get a bit boring after a while.
I find the buffer doesn’t add too much and is pretty transparent tou just get better. I’m often surprised it doesn’t add more of the tube sound.

Anyway, you should enjoy it, most people do. Do give me an update.

What system do you have by the way? And lastly thanks for all of this. I could not be more into audio and it has transformed my system and listening.

Thanks Yatsushiro too.


What system have you got?

At the moment Kii Three in my studio and Naim Nait + Sonus Faber Toys at home (this is where I will place the buffer)

Very nice…I always thought the Kii’s look very interesting, I’m keen to hear them.
I’m using active studio monitors too, nowhere in your league but still one of the best speakers I’ve heard/owned. (HHB Circle 5 - made by Harbeth). I’ve had a few pairs of Sonus Fabers, I used to run Klassic Audio, buying and selling hi-end and vintage, the Electa Amators I remember being really good.
On a separate note is there any news on the YouTube app? Do you think this will ever return?

Oh, and another bargain, possibly even better value are a pair of headphones made by a far east company called KZ.
I honestly dont think there can be a bigger bargain in audio gear. They are one of the biggest non western headphone manufacturers, have been very successful and gained a pretty big following.
They are just incredibly cheap, stupidly cheap. I dont know how that do it.
I bought the KZ ZSN. They do an updated version called the ZSN pro. I didnt think these looked as good and looking at the construction thought the were possibly designed to get the production costs down.
Anyway, the KZ ZSN are proper IEM’s. Detachable leads, twin drivers, one of them the better expensive balanced armature. This post has got long… I’m not related to the company and have no benefit.
They sound absolutely fantastic. Incredible extended bass, nice throughout the frequency spectrum, nothing to fault them. They sound accurate expensive and nice to listen to… I have a pair of £100 AKG in ear headpones. They dont come anywhere close to the ZN. One guy said they’re better than his £300 Shures. Then sound as good sometimes a bit better than my Harbeth (old, cheaper DPM1 speakers). I hate to say that
Anyway, enough. The next bit you either wont believe me or think these wont, cant actually be that good.
They cost around £11 or near on Ebay. In the old days these would have been £150.
BTW, a good fit of the foam tips is really important, its sensible to buy some of the memory foam ones which have multiple benefits.
Please post if you give them a try. You’ll love them.

Hey Michelangelo,

Did you ever receive your tube buffer? Any comments…


I have what most would consider audophile main system- Tube Preamp, OTL Tube Amp, Reference 3A DeCapo I speakers.

However during summer months, I must sideline the tube amps. Temps here in Vegas are > 100f every day now.

So I pull out the breeze audio chip amp and it sound pretty anemic in comparison to the tube amps.

UNTIL I run the source line level through a Musical Fidelity tube buffer!

It really works! 80% of the tube amp sound from a $60 amp (I upgraded the amp’s internal caps which cost me $30). The tube preamp cost me $500 as a kit and the tube amp cost me $2400 factory assembled.

What got me into tube buffers was the Musical Fidelity X10d like you. I got it in a job lot of gear, was sceptical and not a big fan of the company but amazed how a small cheap component upgraded the system. Someone offered me a lot so I sold it years ago. Not so long ago I bought the FX Audio version, a lot cheaper. I cant compare them but have read they sound pretty similar. So much fun for the money. Hi-end audio is getting cheaper, especially if you know where to look!