Reliable 6550 tubes

[FleshOnGear]

I hope the 6550 equipped Marshall users will chime in here. I’m looking for the most reliable, long lasting current production 6550 to use in my Fryette Power Station. I currently have a pair of genuine Svetlana (actually pre Winged C) KT88s in it now, but they’ve gone microphonic. I want something built like a tank, because 6550s are so fucking expensive now that I figure I need to buy once, cry once.

So, what do you think? My gut tells me one of the Reflektor built tubes would be a top choice, but they make so many varieties (Sovtek, EH, Tung Sol, etc.) that it’s hard to tell the differences. Thanks, folks.

 

[PelliX]

So, what do you think? My gut tells me one of the Reflektor built tubes would be a top choice, but they make so many varieties (Sovtek, EH, Tung Sol, etc.) that it’s hard to tell the differences. Thanks, folks.

There have been reports of poor insulation values (cathode follower setups, mainly) from there. I can't say that I've tested or witnessed this, but there's that. As for the difference between Sovtek, EH, TungSol, Mullard and all the other names - often there is none. In some cases a brand will demand a certain spec, but the run-of-the-mill stuff is literally just a different name, often. Caveat emptor.

but they’ve gone microphonic. I want something built like a tank,

Well, any valve can go microphonic. I've always found JJ to be structurally reliable, but a guarantee is hard of course. Some of the Chinese stuff really looks a bit precarious to me, but it seems to be rugged enough in practice.

 

[Matthews Guitars]

Get Tung-Sol KT120s. They'll replace 6550s and won't be running even close to their max ratings. They should be "forever" tubes in this application.

 

[FleshOnGear]

Get Tung-Sol KT120s. They'll replace 6550s and won't be running even close to their max ratings. They should be "forever" tubes in this application.

I’m concerned they won’t fit in the Power Station. It’s kinda tight in there.

 

[Dogs of Doom]

I’m concerned they won’t fit in the Power Station. It’s kinda tight in there.

can you post an image of the space?

The Psvane KT88, are dubbed KT88 / 6550 at many stores...

Psvane HiFi KT88 | HiFiPART STORE

China Psvane HiFi KT88. KT88 is a beam power tetreode, its anode limited dissipation power is 42W. In the audio amplifier, the power can be 100W when it is used as push-pull class AB1 with double tubes, it can also be used in electronic voltage regulator circuit. KT88 is similar with CV5220 and...

www.hifipartstore.com

$75/pair
$150/quad
$310/oct matched
$300/ 2- matched quads

these though are big bottle (wide) for 6550 / KT88

 

[Dogs of Doom]

Shuguang 6550 $114/quad

Shuguang 6550B | HiFiPART STORE

Chinese Shuguang 6550B. The beam power quadrupole 6550B has an anode limiting power of 35W (42W). In the audio amplifier, two tubes A1 and AB1 can be used for push-pull output and reach 100W power. The 6550B can also be used in an electronic voltage regulator circuit. The 6550B is similar to...

www.hifipartstore.com

 

[PelliX]

can you post an image of the space?

That 12AX7 is already close. You're not going to get more than a half a bee's dick clearance with KT88's...

 

[Dogs of Doom]

That 12AX7 is already close. You're not going to get more than a half a bee's dick clearance with KT88's...

right... so no big bottle 6550's either... doesn't look like it would house any of the bigger tubes, but, then they are more expensive anyway...

I'd maybe consider the Shuguangs, as they seem cheap @ $60/pair...

 

[FleshOnGear]

I actually did fit KT88s in mine. It is tight. I was mainly concerned about the KT120s suggested above, because I think they’re much taller.

So, @Dogs of Doom, you’re thinking go with cheap and hope for the best? It’s true that I could buy two pairs of Chinese tubes directly from China for less than one pair of anything else from a US distributor. If one set dies, I pop in the next set and try to redeem the warranty on the bad pair. That might be an ok plan!

 

[paul-e-mann]

Find some old GE that test good.

 

[Dogs of Doom]

I actually did fit KT88s in mine. It is tight. I was mainly concerned about the KT120s suggested above, because I think they’re much taller.

So, @Dogs of Doom, you’re thinking go with cheap and hope for the best? It’s true that I could buy two pairs of Chinese tubes directly from China for less than one pair of anything else from a US distributor. If one set dies, I pop in the next set and try to redeem the warranty on the bad pair. That might be an ok plan!

tbh, I don't know much about the Freyette, but 6550's & KT88's are generally robust tubes.

If KT88's fit ok, then I'd might go that route. I was looking at the image, of the unit & it seems that the small bottle 6550 are what it's designed around. I have the Ampeg VL-501, which has a switch to go from EL34 - 6550 & back. I believe all of Lee Jackson's amp designs also have this.

On his site, he used to have an amp faq, & someone asked about 6550's, & Lee mentioned that you can not use the big bottled 6550 tubes, because they physically won't fit. (in the Ampeg) The tubes will be touching & slightly tilting because of the contact... plus, you don't want tubes touching. They'll be colliding during transport as well...

So, looking at the image, that was my thought, that you probably would be better off w/ small bottle 6550 tubes.

If you look through that site I linked above, search for KT88 & 6550, you should find a few options. That store is a China direct store. I ordered from them, but, they have 2 sites. The one I ordered from, was different. I steered Steve to this one & he got good service...

The best Psvane and Shuguang Tube suppler

China-hifi-Audio Tube Amplifier online store, Willsenton, Boyuurange Reisong, SoundArtist, Yaqin audiophile valve amp, hi-fi Cables for sale

China-hifi-Audio online store : - Dussun solid Amplifier HiFi Audio Shanling Auido vacuum tube CD player E&T hifi audio Racks Stand table ToneWinner Home Theater AV amplifier JungSon Audio Amplifier & CD player Xindak Cables & Amplifier Opera Audio Consonance amp&CD player Bewitch vacuum tube...

www.china-hifi-audio.com

at the China Hi-Fi store, they have a Shuguang Western Electric?

Shuguang WEKT88 PLUS electronic tube Hi-end Western Electric valve one Pair, China-hifi-Audio Tube Amplifier online store, Willsenton, Boyuurange Reisong, SoundArtist, Muzishare, Yaqin audiophile valve amp, hi-fi Cables

China-hifi-Audio online store Shuguang WEKT88 PLUS electronic tube Hi-end Western Electric valve one Pair - Shuguang WEKT88 PLUS electronic tube valve Hi-end Western Electric one Pair 100% Brand New The price is for one pair of Shuguang WEKT88 PLUS vacuum tube Declaration All items...

www.china-hifi-audio.com

but only have 1 pair...

I wonder if they're any good? did they steal WE plans?

 

[Matthews Guitars]

https://www.tungsol.com/specs/kt120-tung-sol-specs-curves.pdf

That has the physical dimensions of the KT-120 in addition to its electrical parameters.

 

[Purgasound]

Sheesh... Just get something affordable. The NOS route doesn't yield dollars for tone. I have never seen the point in spending the extra money when there's no guarantee any of them will last. My cabinet is full of tubes, old and new. While I found the old Svetlana 6550B's to be great, I don't think you can find those anymore. The 6550C's are still pretty good. Why do I prefer those? No real reason other than I've had good luck with them and I like the color scheme on the box... I believe most buyer's perception on tubes is based on the same thing. The mind is made up before the tubes are even purchased in some cases. They call it "confirmation bias". Otherwise you'd think tube sellers would supply frequency graphs from a spectrum analyzer and performance charts...

I'm an outlier when it comes to tube myths. I view them as a component just like any other part of the amp. They either work or they don't.

I sell new matched sets to my customers but many of my personal amps just have assortments of old tubes in them. I buy cheap ones off the internet, singles or lots, and match them up with my tester. I'm not super picky but I do come across a lot of duds. It's almost as bad with new production. The failure rate is pretty high but then again I'm going through multiple sets a month for clients and restorations. For someone only buying a set here or there, you'll likely be fine.

Buy from a reputable seller, with a warranty if possible. The problem with the smaller sellers and one-man white label operations is that they're getting bottom of the barrel junk for pennies and barely putting them through any real testing. I hate to speak ill of anyone in the business but the Nesstone labeled tubes are the worst I've ever seen. I purchased dozens of tubes from them
Nice enough guy and the old used tubes had worked great but the new production ones under their brand have a 1 in 6 failure rate. It's that bad. I'm talking redplating, runaway bias, glass not secure in the base, no getter, excessive current draw, internal shorts, you name it. Those EL34's and 6550's from them were no good. The customer service was good, I definitely mentioned the problem with the glass not glued in the socket and the ones with no getter. Those should have never been shipped out and they sent out replacement tubes with no hassle. I gotta commend them for that but it doesn't change the fact the tubes are terrible. I can't put them in any customer's amp because I get a lot of out-of-town clients.

I just talk too much...

 

[playloud]

Just buy GE. They're surprisingly affordable (certainly compared to GEC KT88s!) and really robust. I'm running a pair now in an amp with high screen and plate voltages.

You see new in box Mesa-labelled ones come up for sale quite often. I think the sellers aren't often aware if they're American made.

 

[FleshOnGear]

I took a chance on the Psvane Horizon 6550s that are sold through Amazon. More expensive than buying direct from China, but they have a 12 month warranty, and they are supposed to be nicer than the standard Hifi series. Plus, they came in one day. They look sturdier than what I’ve seen of Shuguang 6550s. I just unboxed one, and it looks really well built. It has nice thick glass, mica supports at the top and bottom, and extra metal supports surrounding the plates. We’ll see how they do.

The only thing that concerns me is having to do any customer service through Amazon. Apparently Psvane has decided to sell these directly to US customers through Amazon, and I’m not really sure how to redeem the warranty if I have a problem.

 

[FleshOnGear]

Btw, I was just inside my power station to replace the tubes, and it’s clear that the KT120 would NOT fit. Based on the datasheet posted above, compared to the datasheet for the KT88, the KT120 is about 5/16” taller. There is very little clearance in the Power Station for a 6550 or KT88.

Here’s a pic of one of the Psvane Horizon 6550s:


It sounds good! I can’t say if there’s a noticeable difference from the old Svetlanas I had in it, but these Psvanes are at least quiet. Maybe these are are bit more forward in the mids, but I can’t tell if it’s my imagination. It takes awhile to take apart the PS and put it back together, so it makes an a/b comparison difficult.

 

[StingRay85]

Invest in a pair of NOS GE 6550A. They will last forever

 

[FleshOnGear]

So the pair of Psvanes I got make a steady clicking sound, about 3-4 clicks per second, which is pretty irritating. Here’s where buying from Amazon seems to pay off. I clicked on the returns link, then answered whether or not I wanted a refund or replacement, and where I wanted to drop off the return. Another pair is coming tomorrow, and as long as I bring the first pair to the UPS store down the street by Sept. 16, I won’t be charged anything. I don’t even have to pack the tubes into a box.

The only issue I see is that I don’t know if it will be that easy if I have a problem months down the line.

 

[Dogs of Doom]

I wonder it there's an incompatibility problem w/ the Fryette...

IDK if Freyette answers emails, you might ask him about this. I would, either way.

The only time I experienced anything, like what you're describing was, trying to put12AX7 in the power tube slot of my JVM1h. It didn't click, but, the sound cut out, on cycle & when the sound was on, it sounded bad. The only way to describe it, was it sounded like the amp was broken.

 

[aberry9475]

Invest in a pair of NOS GE 6550A. They will last forever

Can confirm, the old coke bottle 6550's will just fit in the PS because that's what I'm running!