REVIEW: Blue Circle Audio “Hat Peed Thingee” solid state Headphone Amp
May 28, 2009 at 9:53 PM Thread Starter Post #1 of 63


Reviewerus Prolificus
Apr 30, 2005
The Court of the Crimson King
In the Beginning...

Gilbert Yeung is a free thinker. All you need to do is take one look at the Hat Peed Thingee (henceforth “HPT”) to realize this. I have never seen anything like it. The “chassis” is PVC pipe, and the innards are all completely encased in silicone. I cannot imagine anyone thinking it looks “good, or “nice”, but beauty is in the eye of the beholder, so here you go:





I previously reviewed the Blue Circle Audio SBH, and I was so impressed I bought one, which was my main headphone amp until I became a complete tube junkie. The $1,300 SBH, I felt, as nearly as good as the $2,500 RSA Apache. BCA is big on building serious power supplies, and I am certain that this was a big part of what made the SBH such a great sounding amp.

And while that might be true with the HPT, we will never really know – since all the parts are completely invisible, we have no idea what is actually in this thing. I know that is going to make some head-fiers absolutely apoplectic, but it is what it is. One must, in this case, just listen – there is truly nothing to see.

There are actually quite a few configurations of the HPT:

Hat Peed Thingee with standard power supply USD549.00
Hat Peed Thingee with Biggie Pipe power supply (includes a ground lift switch and IEC input) USD749.00
Hat Peed Thingee with SP Capacitor Pack and standard power supply USD949.00
Hat Peed Thingee with SP Capacitor Pack and Biggie Pipe power supply USD1149.00
I did most of my listening to the $1,149 version. But I did listen to each of the configurations, just for yucks, and I will report on those later.

As always, all listening was done at my calibrated listening level of 80dbA using pink noise. I used the Beyer DT880 and JVC DX1000 mostly for this review, but did also use the DT990 at times. Sources were my Denon DV5900 universal player, my vinyl set-up, and an iMod iPod with V-Cap dock.


In its ultimate configuration, the HPT provides what I consider to be state of the art sound for a solid state headphone amp – dead neutral frequency-domain performance, including very extended treble and bass; jaw-dropping transparency; lightening-fast transients; and powerful dynamic capability. And the HPT accomplishes all of these. I was able to compare it to the ALO Audio Amphora, and it was only during this comparison that I noticed that the Amphora is just *very* slightly soft at the top, and that it is perhaps just ever so slightly euphonic. Not nearly as much so as even my fairly neutral Singlepower Extreme, but the HPT is more neutral even than the Amphora, which I had not thought possible.

I actually thought that both the Amphora and Extreme seemed to be just a little more transparent, though. And here I do not mean neutral at all, but there were times I felt like the HPT had a tiny bit of a “white” or “chalky” overlay to it – nothing significant at all, but in this regard it was not the quite the equal of the Extreme, or the Amphora.

Further, the Amphora and the Extreme both image better than the HPT. The HPT does not have the same degree of holographic soundstage, nor the ultimate width or depth that these other two similarly priced amps have. Again, the differences are slight, but real and audible, and at $1,300, I expect the best. The HPT does score slightly behind the amps I have in the same price class in this regard.

On the other hand, the HPT was more neutral than the other two. Again, just slightly, but again, audibly. I’m not sure it’s possible to make an amp with a more neutral frequency balance than the HPT. That did, of course, mean that good recordings were wonderful, and that bad ones were…well…bad. But such is the two-edged sword of neutrality – no editorialization. This also is NOT the amp to “correct” problems with your headphones – you will hear your headphones exactly as they are.

I wish I still had the SBH on hand, because my recollection is that the SBH was slightly less neutral (in that it was a little lightweight in the bass), but just a little more transparent. But without the ability to directly compare, it’s impossible to say since these are such slight differences I am describing.

After further review...

What was fascinating, however, was that the BASIC configuration of the HPT was very nearly as good as the full-pull version. The main difference was in smoothness – the combination of the cap upgrade and the enhanced power supply was smoothest. But I was bothered by the fact that in some ways, I actually thought I PREFERRED the basic version! Something seemed odd about this, but it was MORE transparent, IMO, than the full-up version.

After some period of time with the basic configuration, I went for the HPT with upgraded power supply but NO cap upgrade. WOW. Now we were getting somewhere! This $749 configuration was, actually, the best sounding, IMO. I tried then putting the “cap upgrade” module in and out, and there was just no doubt about it – the cap upgrade actually REDUCES the transparency. I was shocked, but there it is. The cap upgrade mad the sound a little smoother, but at the noticeable expense of transparency. Not sure what is going on there, but I went back and forth repeatedly, and always had the same opinion. While the PS upgrade at $200 seems worth it to me in terms of providing a little more bass authority, and a little more dynamic swing, the $400 “cap upgrade” is actually a problem, IMO, and shouldn’t be considered.

Just as an example of this, if you listen to Peter Tosh’s “Downpressor Man”, there are some very meaningful nuances to his vocal that actually got muted by the Cap Pack. They were more clearly heard without it in the chain. Odd, but true – I checked it several times.

Comparatively speaking...

I compared the HPT “basic” to the Audio-GD C2C, and felt that the HPT was both slightly more neutral and slightly more transparent than the C2C, with slightly better dynamics. I have to confess that the C2C is so good for the money it is hard to say that the $200 price difference between it and the HPT is definitively worth it, but the HPT is still better at the end of the day, and enough that I recommend spending the extra jack if you have it to spend.

Versus the $749 HPT with upgraded PS I still feel the Extreme and Amphora are slightly more transparent, and soundstage better, but now we’re talking about an amp that sells for 30% less – and as such is a VERY good value IMO. Would I personally buy the HPT versus something like the $795 Decware CSP-2? No. I am a tube junkie, and I prefer the slightly euphonic, lush midband performance of the CSP-2, with it’s jaw-dropping soundstage. But on this point, YMMV, and of course I have $250 worth of tubes in my CSP-2…

After all...

So as either the $549 basic or $749 with upgraded PS, the HPT is a terrific value in a SS amp, providing excellent performance. Just save your money on the Capacitor pack – go buy some music with that $400, and thank me later
May 28, 2009 at 10:14 PM Post #3 of 63
Thanks! For me, transparency is the degree to which you are provided a feeling of having nothing between you and the music - just a wide open window. Many audio devices ahve some degree of veil, haze, glaze, thickness, or other "interference" between the music and the listener. It is one of the most important aspects of audio reproduction, for me.
May 28, 2009 at 11:18 PM Post #4 of 63
Thanks Skylab, great pics (weird looking thingee), excellent read. I have always enjoyed your reviews from start to end, no BS approach loving it.
May 28, 2009 at 11:26 PM Post #6 of 63

I should add: while the HPT may look odd, it is solid as a rock in terms of how it is built. Unusual, yes, but it would probably withstand a 10 foot fall onto concrete with just a scratch.
May 28, 2009 at 11:34 PM Post #8 of 63

Originally Posted by .Sup /img/forum/go_quote.gif
so how do you fix this if anything goes bad?

Send it back to the dealer or manufacturer is the only answer, I think.
May 28, 2009 at 11:44 PM Post #10 of 63
It would also serve to provide dampening of vibration, although I'm not sure how much impact that has on the sound (though clearly some people think its impact is significant).
May 28, 2009 at 11:55 PM Post #12 of 63
I'm not sure - does silicone make an effective shielding agent? Someone else will have to tackle that one
May 29, 2009 at 12:27 AM Post #13 of 63
Nice review.

I had a chance to meet Gilbert at AKFest in Livonia, MI not too long ago. Interesting guy with a great sense of humor. He was sporting a capacitor that was to be used as a power supply in some application. Unfortunately, I didn't get a chance to get back around to visit his display. My loss...

I found your comments about liking the basic version better to be interesting. I've occasionally found that an amp that received a power supply upgrade will often smooth out significantly, have better separation and fine detail...but occasionally be "less fun" to listen to in it's upgraded form. The amp loses some of it's forward presentation, and has less umph. Do you think this was an example of this, or was it something else?

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