Yamamoto HSA-01 headshell/head amp

During my recent trip to Tokyo, I happened upon this gadget. It is a headshell with a built-in gain stage that boosts signal voltage in the ratio 1:14. Apparently this is achieved via a tiny op amp and battery power, both seated in the base of the headshell, behind the phono cartridge mounting area. The beauty of the idea is you can thus boost the signal of a very low output LOMC right at its source, before it has had to travel over connectors, tonearm wires, more connectors, etc, to reach the first stage of gain, be that a head amp, SUT, or high gain phono stage. The op amp is designed to drive a 47K ohm input resistance and is thus suitable for MM stages or a low gain MC stage in which the load is 47K ohms. The net weight is only 12.5g, making it somewhat compatible with even high compliance very low output cartridges. I wonder if anyone has experimented with this gadget. I am about to do so myself.


Dear Raul, you are an amazing historian of this hobby. I personally do not recall any similar product, but if you say it existed, I believe you. However, I would think that a modern iteration of the product would likely be superior to anything that Was on the market 20 or 30 years ago, simply because the gain devices we now have available are both smaller and superior in performance to anything that was possible back then. This does not necessarily mean that the thing I bought in Tokyo will be a revelation. I will report eventually on its performance.  my reason for starting this thread was simply to find out if anyone here had already heard the device in action. 

I heard a fet based front end mounted at the headshell end designed and built by Peter Suchy in the mid 80's at CES. Only difference was that he ran an external power supply with wires running through the arm tube. I never saw this go into production though.

In fact in Japan there have been a number of these head shell based gain stages through the years. This one is one of the tidiest implementations I've seen.

If they had mounted it on top of the head shell there would have been no cartridge limitations.

Of course in the old days Ortofon had mini SUT's built into their low output cartridges in their integrated head shell with some models.



My rationale for giving the HSA-01 a go in my system is purely to see how it works with the Ortofon MC2000, which puts out only 0.05mV at standard velocity. So far, the MC2000 works well with a head amp built for me by Dave Slagle, driving my much modified Silvaweld 550 in MM mode, and with both my modified Atma-sphere MP1 and Raul’s 3160 Phonolinepreamp, set for hi-gain. Using the HSA-01, the MC2000 output goes from 0.05mV to 0.7mV at the headshell. I want to try it driving either of those latter two phonolinepreamps, with input Z set to 47K ohms. This would say something about the negative effect if any of the wires and connectors between the cartridge and the phono inputs on such a tiny signal amplitude. (Well, we know wires and connectors can have negative effects, but are they ameliorated with a higher voltage output from the headshell?) Also, the HSA-01 would enable me to use the MC2000 in my Beveridge system, which is driven by a Manley Steelhead that only manages 65db total gain at max.

Dear @lewm : You are rigth today op-amps are way better that the ones in the 80’s.

I’m with you that bougth it more by " curiosity ".


" will be a revelation ". I think not because it has very limited frequency range ( I can’t understand why is that but was what Yamamoto choosed. ) and you don’t know its levelnoise that I magine should be low but we don’t know.

Normally headamps has a frequency range from 0.5hz to over 500khz and some -3db at 1Mhz, this is another history and not a " open door " for this thread.


Yes, share with us what you experienced with.


If you say so.  But I personally would not call flat from 10Hz to 100kHz "limited".  If you use -3db limits, then perhaps the bandwidth is much wider.