Anyone use SHUGUANG tubes?

[Tone Meister]

I recently bought some Shuguang EL34-B tubes from Weber to use in a couple of amps...[/url]

What is your impression of their performance and longevity?

[PeanutNore]

Do you find a stage limit? (3-stage/4-stage/etc)
Or is there a preferred 'management' method while culling frequencies back between each stage? (eg: a flat 5-10% at each stage, or just a formula relative to the gain of each stage? eg: 20% gain stage = 20% culling)

I mapped out the lead channel preamp of my 6505+ which has 6 stages, and after the 4th stage they start using interstage voltage dividers and no cathode bypass caps to manage things. If you are using 3 or 4 cascading gain stages I don't think you really need any tricks.

[Chuck H]

I had the chance to hear the EL34B's next to four different pairs recently. The pair I received were a little microphonic right out of the boxes so I don't expect them to last but they were the best sounding of the bunch and, incidentally, the only ones to survive!!!. The amp was a custom job with 475Vp. I didn't think that was unreasonable for EL34's, but maybe it is for modern ones. I tried some older Sovtek fat bottles (apparently older than I'd thought as. POP), new JJ EL34L's (one shorted heater to cathode the moment it was clipped), Sovtek EL34G's (also pulls I had around. one went slowly dead as the heater faded), new Tung Sol EL34B's (arching internally) and some 6L6's I had around (these lived but didn't sound as good with the bias trem as the EL34's). I was starting to think it was the amp until the 6L6's survived. Two sets of new Rusky EL34's suffered different failures right out of the boxes! The amp IS working correctly. I checked and rechecked all operational parameters. Sounding great for now with the Ruby EL34B's (Shuguang)...

Audiotexan, Don't read too much into anything. It's not part of some grand design philosophy or anything. Some amps sound good with lower voltages in early stages. The way I'm using it, plate voltage and how it makes a tube behave is just one ingredient among many. Basically, running a tube high and tight improves gain and clarity. And yes it SHOULD follow down the line because whatever is happening in the early stages is getting amplified the most, right? But if one were to JUST raise the voltage in a cascade preamp it could result in more LF and HF available for further amplification. Simple as that. And IMHE it's excess LF that results is buzzy preamp clipping. If you look at a lot of high gain preamp schematics you'll notice a trend in voicing that trims LF in the earliest stages and HF in the later stages. It's the easiest way keep the tone from being flabby and buzzy and generate audible harmonics without being too bright. And I think it's a good framework to start with if designing a high gain preamp. The higher voltage, with proper voicing, seems to give a little clarity that I prefer.

[Tone Meister]

I bought one quad of the Shug EL34s for an amp with relatively low plate voltage (<400) and one tube had run away bias right off so I didn't have a chance to assess them the way I wanted. The tube was replaced, so I still have the quad and want to give them another shot.

I've had excellent results with the Ruby preamp tubes, so I think I'll give some of the regular Shugs a fair shot. Certainly can't beat that price.

[Alan0354]

I recently bought some Shuguang EL34-B tubes from Weber to use in a couple of amps. They don't sell matched tubes, so I bought extra and matched them up myself in the amps. They weren't greatly mismatched across the lot of 5 either. In the past, the tube pins came with extra solder blobs that needed filing to fit the sockets. The latest batch have pins that fit the sockets right out of the box. Shuguang must be responding to customer complaints, and that's a good thing. Weber is a good source for the tubes, as their prices are reasonable - $9.25 each, and they ship quickly.
https://taweber.powweb.com/store/tubeord.htm

Ebay is cheaper and free shipping.

Watch out, twice I have problems with their products. First, the power transformer I bought have unbalance winding, they sent me 2 before they discovered all of that model have problem. They end up sending me a more expensive alternative. Then their DPDT power switch all have intermittent problem. I got 6 and all had problem. They claimed they never heard of any complain, but they sent me 6 new ones. I have not have time to test it yet.

I will still buy from them as they are cheaper and they tried hard to make me happy, but you need to watch out and check things carefully.

[Alan0354]

Audiotexan, Don't read too much into anything. It's not part of some grand design philosophy or anything. Some amps sound good with lower voltages in early stages. The way I'm using it, plate voltage and how it makes a tube behave is just one ingredient among many. Basically, running a tube high and tight improves gain and clarity. And yes it SHOULD follow down the line because whatever is happening in the early stages is getting amplified the most, right? But if one were to JUST raise the voltage in a cascade preamp it could result in more LF and HF available for further amplification. Simple as that. And IMHE it's excess LF that results is buzzy preamp clipping. If you look at a lot of high gain preamp schematics you'll notice a trend in voicing that trims LF in the earliest stages and HF in the later stages. It's the easiest way keep the tone from being flabby and buzzy and generate audible harmonics without being too bright. And I think it's a good framework to start with if designing a high gain preamp. The higher voltage, with proper voicing, seems to give a little clarity that I prefer.

Yes, it was good advice from you a while back when I first started seriously into designing guitar amps.

Also, I ran the amp at higher volume this morning. Yes, raising the plate voltage on the first stage seems to reduce the horn sound of the Shungang. At 240V, the difference in sound between JJ and Shungang is minimal. JJ still seems to be slightly brighter, but that can be adjusted out.

There is so many little things about sound that you just cannot explain with electronics that it becomes an art. It's like after I do basic trouble shooting and verification when I first build and power up the amp and check for noise, hum, oscillation etc. After everything looks right, I can put away the scope and generator all together. Then come the touchy feely stuffs.

[Audiotexan]

Audiotexan, Don't read too much into anything. It's not part of some grand design philosophy or anything.

Much appreciated reminder, and fair enough!
I know there's a thousand different schools of thought, with different goals and approaches, that's why I was trying to keep it 'generally speaking'.

Some amps sound good with lower voltages in early stages. The way I'm using it, plate voltage and how it makes a tube behave is just one ingredient among many. Basically, running a tube high and tight improves gain and clarity. And yes it SHOULD follow down the line because whatever is happening in the early stages is getting amplified the most, right? But if one were to JUST raise the voltage in a cascade preamp it could result in more LF and HF available for further amplification. Simple as that. And IMHE it's excess LF that results is buzzy preamp clipping.

Makes perfect sense.

If you look at a lot of high gain preamp schematics you'll notice a trend in voicing that trims LF in the earliest stages and HF in the later stages.

Ok! This is more along the lines of what I was looking for. And will definitely put a bit of time aside to focus on those! Thanks again!!

I mapped out the lead channel preamp of my 6505+ which has 6 stages, and after the 4th stage they start using interstage voltage dividers and no cathode bypass caps to manage things. If you are using 3 or 4 cascading gain stages I don't think you really need any tricks.

Interesting! Haven't been 'up-close-n-personal' with any newer Peavey stuff in long awhile. Appreciate you mentioning that PeanutNore!

[Diablo]

What is your impression of their performance and longevity?

I don't have a lot of hours on the tubes, so I can't really say anything about longevity. In the past, I never had any reliability issues with the Shuguang EL34B. They sound good in my amps, one is a 5E8A tweed twin, and the other is a Magnatone M13. I'm just happy they aren't noisy out of the box, and the bias is good and stable.

[potatofarmer]

I have, well, HAD a quad of Ruby 6L6 in my Twin. One tube's envelope broke neatly around the base. The envelope glass seems very thin, but then I mostly have old tubes in my amps. I do gig with this amp so I assume it's on me, but are Shuguangs unique in this regard, or is this the case with all new production tubes?

[Alan0354]

Tubes are fragile!!! I pulled out two of the 6L6 from my Pro Reverb, next thing I know, one was all shattered.

I just bought 4 Shuguang EL34 for $38.50. The two I have absolutely mismatched, one almost double the current of the other one.

[PeanutNore]

Thought I'd put this here instead of starting a new thread - interesting article that Google Now on my phone found for me this morning after I was searching for Shuguang tubes last night:

Shuguang Vacuum Tube Manufacturing Article By Rachel Of Grant Fidelity

[PeanutNore]

Thought I'd put this here instead of starting a new thread - interesting article that Google Now on my phone found for me this morning after I was searching for Shuguang tubes last night:

Shuguang Vacuum Tube Manufacturing Article By Rachel Of Grant Fidelity

[Leo_Gnardo]

I have, well, HAD a quad of Ruby 6L6 in my Twin. One tube's envelope broke neatly around the base. The envelope glass seems very thin, but then I mostly have old tubes in my amps. I do gig with this amp so I assume it's on me, but are Shuguangs unique in this regard, or is this the case with all new production tubes?

Woops, I didnt see this 4 weeks ago. I've had glass break on tubes of all vintages, including current Shugugang, JJ, and all the brands under the New Sensor roof. About the only sure thing I've found to avoid, is using Sovtek 5881 wafer-base tubes with "bear trap" style retainers. The bear trap steel doesn't grab the glass, and raps against it in shipping or rattling around in the back of the equipment truck. Other Sovtek, EH, etc. New Sensor tubes even with thick glass, some break anyway. And it's a real shame when a nice NOS tube loses its vacuum with or without obvious shattered glass. It's all part of the fun.

- - - - - - -

Alan, which type of Shuguang 6L6GC did you get? There are 2 main types besides the "specials" made for TAD, Gold Aero and other distributors. There's a large-envelope 6L6GC that closely resembles the Sylvanias that were STR'd for Fender and later Mesa. I find those are pretty darn good tubes but occasionally I get one that's a bit rattly or microphonic. Then there's a small-envelope one that's not very reliable in general. Besides the size of the glass envelope, you can tell the lesser ones because all the electrodes coming up from the base are arranged in a straight line and crimped in a fold of glass. Some of those work OK, but many are crap.

If you bought your tubes from a reliable distributor, say CE/Antique or Mojo or Ruby/Magic or Upscale, a couple others, the match should be acceptable. If you got a cheapie deal on Ebay, can't expect much. You get what you pay for. A couple more $$ should get you a well matched set of good working tubes. A good distributor will cull out dodgy tubes, pitch 'em in the rubbish bin where they belong. You can see how that will raise the price of the remaining good ones, plus the labor involved in testing and matching.

Back in the bad old days, late 70's when it looked like tube manufacturing would cease forever, I remember going to a local parts store, Greylock Electronics. I needed 4 6L6GC for a Twin or something, and got RCA's. Don't get too excited, by that time RCA had quit making their own terrific "black plates" and these were Sylvanias actually, with RCA paint on 'em. Still good tubes. I asked the counter man, who I knew to be a super cynical "type" if I could get a matched set. "HA! They're all the same brand - there's your matched set" was his answer. He rang 'em up, I paid him and out the door I went.

[g1]

"Pursuring remarkable Dawn incomparable" is this some kind of clever marketing, or just to show they are authentic?

[Alan0354]

Alan, which type of Shuguang 6L6GC did you get? There are 2 main types besides the "specials" made for TAD, Gold Aero and other distributors. There's a large-envelope 6L6GC that closely resembles the Sylvanias that were STR'd for Fender and later Mesa. I find those are pretty darn good tubes but occasionally I get one that's a bit rattly or microphonic. Then there's a small-envelope one that's not very reliable in general. Besides the size of the glass envelope, you can tell the lesser ones because all the electrodes coming up from the base are arranged in a straight line and crimped in a fold of glass. Some of those work OK, but many are crap.

Ha ha, I don't have the rich knowledge on tubes, so I take two pictures of the 6L6 and EL34. Let me know whether that answer your question or you want picture from another angle. I got it on ebay.....the cheapest of the cheap!!!!