Agree with @davide256 . CV4003 are rolled off and too "creamy."
Gold Lion KT77 tubes for Primaluna Amp - a few questions
I have a Primaluna Dialog Premium HP amp (stereo mode), and am currently running the stock el34s. With 4 per channel, the re-tubing and tube rolling discussions can get expensive, so I have been treading lightly. Having read numerous threads (lots of great discussions and comments - thanks to everyone who has contributed) I have decided to give the golden lion KT77 tubes a go. I have a few questions.
1- in looking around, I see there a multiple sources of the tubes. From multiple eBay sources (some which appear to specialize in tubes and others that do not, some are “genelex authorized dealers”) to the well known Upscale Audio. The pictures of the tubes all appear to be similar. Am I correct in assuming they are all the same genelex “made in Russia” tubes?
2- one of the things that appears to differentiate the different suppliers is how they match them. Is all matching the same, as long as they are “close enough”? I see factory matched, hand matched, transconductance, plate current, 5%, 10%. Lots of stuff here. ESPECIALLY for the self biasing Primaluna amp, how critical is the matching method?
3- one last question about dealers. I am in the Chicagoland area and I recall somewhere someone saying or posting that they buy all their tubes from a local company, that was very good and knowledgeable. Does anyone know who this dealer is? All things being equal, supporting the local economy (and being able to talk to another audiophile across the counter) is a good thing.
finally, just so we don’t go down a different rabbit hole, I did replace the center two 12au7s with mullard NOS 4003 from Upscale Audio. One of the best things I have done to my system. Wow. I plan on changing the other four, too.
THANKS
Bill
1- in looking around, I see there a multiple sources of the tubes. From multiple eBay sources (some which appear to specialize in tubes and others that do not, some are “genelex authorized dealers”) to the well known Upscale Audio. The pictures of the tubes all appear to be similar. Am I correct in assuming they are all the same genelex “made in Russia” tubes?
2- one of the things that appears to differentiate the different suppliers is how they match them. Is all matching the same, as long as they are “close enough”? I see factory matched, hand matched, transconductance, plate current, 5%, 10%. Lots of stuff here. ESPECIALLY for the self biasing Primaluna amp, how critical is the matching method?
3- one last question about dealers. I am in the Chicagoland area and I recall somewhere someone saying or posting that they buy all their tubes from a local company, that was very good and knowledgeable. Does anyone know who this dealer is? All things being equal, supporting the local economy (and being able to talk to another audiophile across the counter) is a good thing.
finally, just so we don’t go down a different rabbit hole, I did replace the center two 12au7s with mullard NOS 4003 from Upscale Audio. One of the best things I have done to my system. Wow. I plan on changing the other four, too.
THANKS
Bill
27 responses Add your response
I have been curious about trading tubes. I have 8 matched gold lion KT77s from my Primaluna HP amp, with about 30 hours on them. They are from upscale audio, paid 50 each (400 for the set). After some listening, I decided I preferred something else as a better match for my speakers. Rather then have them sit in the drawer, I wonder if there is a mechanism to trade them to someone else for ...... ? I thought about setting up a separate thread to propose this, but since this thread became active again, I thought I’d throw it out there again. unless someone knows of something already set up. bill |
Is it standard practice for a tube supplier to require buyers to return tubes (and pay return shipping) that failed inside of the warranty period, and pay shipping for the tube replacement? That's what I experienced with Kevin Deal from Upscale Audio. Seems like poor customer service to me, but I can see how suppliers want proof that a tube failed prior to agreeing on replacement... but I disagree with requiring the buyer pay shipping both ways. |
I've purchased Genalex GL KT-88's and several other tubes from ebay dealer wpc1896 based in Ohio. Had one tube go bad after several months of use and it was replaced free of charge. Have also purchased from Viva Tubes, Tube Depot and a few of the Chinese dealers on ebay selling Psvane & Shugaung tubes. I've relied mostly upon feedback for the purchases and I'm totally satisfied with the quality of tubes, service and pricing they've provided. The only problem with the Chinese dealers is that if you do get a bad tube, which I have, it can take a several months to get the exchange done for the replacement. They've always made it right though. |
Persistent tube failure! BUMMER...A tube can fail "whenever" but new factory matched tubes from most sellers seem reliable in my experience...ya never know...a 90 day warranty is common, thetubestore.com does 6 months on some...that's about all you can hope for, but new tube failure still seems rare (except for jond maybe) and I've had some tubes last a lot longer than what I expected. Viva, again, seems to test everything they sell and hey...great pricing is always appreciated. |
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If you can solder, its pretty easy to replace the coupling caps. All point to point wiring on the PL amps and pre amps. The SCRs that come from the factory are ok. They are very reliable, which is why so many use them, but the copper foil caps are much more organic sounding. There are several sources on the web, soniccraft.com partsconnexion.com that carry them. the Jensen copper foils have an aluminum outer case, the Jupiter copper foils have an outer cardboard or paper case coated in wax. The PL gear has plenty of ventilation, so have not had a problem with either. I would send a few before and after pics, but don't think there is an option here to post photos. The cap change out is big improvement over stock, If you like the sound of VAC amps, the caps will get you much closer. J |
I run a Prologue Premium integrated. I used to use Mullard CV4003 pre tubes but found as I dabbled with about a dozen others that they rolled off the high frequencies and added some bass distortion. Preferred pre tubes nowBugle Boy 12AU7s in front socketsTelefunken 12AU7s in back sockets In the power tube sockets, I've used Tungsol EL34, new Mullard EL34, Golden Lion KT88's, Tungsol KT-120/150's Tungsol KT 150's were the best blend of tonal accuracy, speed, and low bass authority. KT88's were my least favorite, something weird, artificialsounding about tone color. |
The Chicago area tube dealer is likely Brent Jessee Recording in Hoffman Estates. I've bought many NOS tubes from Brent over the years and can confirm he's a good supplier. I bought my GL KT77's from Tube Audio Store (RAM Tubes), as the owner (Rodger Modjeski) also designed my Music Reference RM9 MK2 amp. |
You should contact Jim McShane thats lives right in your Backyard. I have bought tubes from him for a few years now. He is well known for supplying great tubes at a fair price. http://www.mcshanedesign.net/tubes.htm |
For tubes I tent to avoided E-bay sellers and stick to the larger internet-shops like the Tube store and various other large tube sellers also local audio shops. I find you usually get good quality, reputable people and a return policy that actually is useful if you get a blown tube or failed tube from transit. I also like the gold lion tubes I've run in the past good quality and better sound then most other new tubes out there IMO. |
My KT77s came from a reputable Ebay dealer, and were supposedly "factory matched." They're the best sounding tube I've tried in my SE power amp (only 1 single ended power tube per side), and that list includes KT88s from Sovtek and Gold Lion, Tung Sol 6550s, KT150s, and KT120s...all of the above sounded great (JJ KT77s were also tried and sounded not so great), but the GL 77s are better by a surprisingly large margin. In my amp they might (not sure) lop off 2 watts of the supposed 12wpc I get from other tubes (Dennis Had Firebottle high output amp), but it's not noticeable. |
I've been using the PL HP for a few years. Great amp with whatever tubes used. Matching isn't a concern with the auto bias. The GL KT77's retain the great mids, and you may notice a little more extension on both on both ends. YMMV. Changing the 4 other preamp tubes aren't as noticeable like the 2 gain tubes. |
So it would make sense (in my pea-sized brain) to purchase
the KT-77 tubes from Kevin @ Upscale Audio. You already have one positive
purchase experience with him. Although he’s not the lowest cost provider, you’ll
have the peace of mind knowing that the tubes have been thoroughly tested and
burned in.
For reference I own a PrimaLuna Dialogue 4 and run the same
(Upscale Audio purchased) Gold Lion KT-77 tubes in it. I’ve made many tube purchases
from Kevin over the years and never had a single negative purchase experience
or received anything less than stellar advice/service. |
RAM tubes. CORRECTLY tested and matched tubes by the most knowledgeable tube expert/authority alive, Roger Modjeski of Music Reference. He has supplied tubes to other amp designer/makers such as Mike Sanders of Quicksilver and Ralph Karsten of Atma-Sphere, and approves of and sells the Gold Lion tubes. |