Tubes Asylum: REVIEW: Penta Labs / Shuguang GEKT88 Tubes by Kamigo

Model:	GEKT88
Category:	Tubes
Suggested Retail Price:	$22 Ea.
Description:	GEC KT88 clone
Manufacturer URL:	Penta Labs / Shuguang
Model Picture:	View

Review by Kamigo ( A ) on January 14, 2006 at 15:13:09
IP Address: 207.112.90.195

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I promised to write something about these much-loved tubes after I'd put about 100 hours on them, so here we go.
For the past year or so I've been very happily running OS Tung Sol 6550s in my Audio Note Kits Kit 2 (1 x 6550 per channel). I've been pretty lucky at getting some nice quality TS tubes at very good prices, but the well is pretty dry and they aren't going to last forever. I decided it was time to try out some potential replacements and with the positive buzz around Shuguang tubes, I decided to try out their KT88. But WHICH Shuguang KT88?! There are four to choose from: KT88, GEKT88, KT100 and KT88-98. Since the GEKT88 is reputed to be a copy of the legendary and hyper expensive GEC KT88 (and made on GEC machinery??), I decided to go with that one and ordered an unmatched pair from Penta Labs.
Early on the tubes weren't too impressive, but weren't awful my any stretch. They were a bit lifeless but pretty balanced right out of the box. They sounded cold compared to the TS 6550s, and not as clear at the top.
One hundred hours later and these are the tubes for me! They've really come into their own and sound terrific all across the spectrum. Bass is deep and tight, mid bass is punchy in that "I can hear the air whooshing out of the bass drum" kind of way. Mids are a little warm but very inviting and engaging. Vocals sound wonderful. The highs have opened up and these are the first pentodes I've tried (also GE 6550s and JJ KT88s) that don't have an annoying 'tizzle' on the top end. Detail is excellent, though if memory serves the JJs might have the edge there. Still, with my newly set up audiophile computer source (using Jim Hagerman's Hag USB, EAC and Foobar 2000), the detail - including a real sense of the recording space / room, soundstage and what the weather was doing that day - is fantastic and as much as I could ask for.
Build quality is excellent. The only minor gripe I have is that the tube sometimes (like maybe a couple of times an hour) lets out a small 'tink' noise, as maybe the mica lets some heat go or something.

Product Weakness: A little hard to source. I've only seen it at Penta Labs (who sell it under their name with yellow labelling) and at supertnt.com I'd recommend the latter for buyers outside the US and Penta only uses UPS International Express ($$$) for delivery.
Product Strengths: Bass, mids, treble, detail, build quality, price

Associated Equipment for this Review:
Amplifier:	Audio Note Kits Kit 2
Preamplifier (or None if Integrated):	Integrated
Sources (CDP/Turntable):	HagUSB/PC, Roksan Kandy CDP
Speakers:	Audio Note AN/E
Cables/Interconnects:	DH Labs Q10 speakers, Audio Note AN-V silver and VH DIY silver ICs
Music Used (Genre/Selections):	Mostly classic jazz, but rock and classics too
Room Size (LxWxH):	19 x 14 x 12
Room Comments/Treatments:	None, just a couple of big leather chairs
Time Period/Length of Audition:	100 hours
Type of Audition/Review:	Product Owner

Product Weakness:	A little hard to source. I've only seen it at Penta Labs (who sell it under their name with yellow labelling) and at supertnt.com I'd recommend the latter for buyers outside the US and Penta only uses UPS International Express ($$$) for delivery.
Product Strengths:	Bass, mids, treble, detail, build quality, price