Redtube

Audio innovations Series 500 Amp

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Hey everyone I hope being new to this forum I am not posting in the wrong place, I wonder if I might ask one or two questions about valve choice with my S500.

The amp itself is the original specification type as purchased new in 1990 approx. from Definitive Audio, in Nottingham, it has the usual EL-34 power pentodes and the ECC83 and 88s all of which were replaced a  very long time a go with better quality Mullard ECC88 (NOS type), and Golden Dragon for the ECC83, all still working well, the power tubes were replaced with EL-34 Golden Dragon Premium, as well as GEC 6CA7 (NOS type).

I am thinking of purchasing a new set of tubes, especially the power tubes, and I was thinking of the Shuguang 6CA7 Black Treasure but these are expensive and I am concerned about longevity, I hear a lot about 5881s, what do you recommend. Also any other bits of advice much appreciated.

Thank you

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Moderator

Hi welcome to the forum , you have posted in the correct section , that bit I can help you with , your query I can't but somebody will be along shortly :)

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Super Dealer

Hi,
I've serviced /upgraded a dozen of these this year's I there's plenty out there! Clients split into three camps for valves: NOS which are expensive, 5881s which are very smooth across the range, and kt77s which offer a bit more punch across the range. I'd probably go with Genalex kt77s myself

David

Sent from my ONEPLUS A5000 using Tapatalk

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Hi Redtube and welcome,

If you can get nos Ei 6ac7 fat boys that would be my choice, i still use mine now and again. The 5881s are ok but not for me but they may suit your taste and system.

6CA7EI.jpg

I also have and like the Svetlanas 6ac7 (older ones, fat boys) but again hard to get now. The Golden Dragons i also have, good but a bit laid back sometimes. The Sovteks el34G are ok and cheaper than all the rest and are very similar to the current Sletvana C Wings in my opinion. Also i have tried Mullard nos but not worth the money in my opinion, stupid price !

Also try a Sovtek 12ax7lps (ecc83) in place of the golden dragon, i find them very good.

These are interesting but haven't tried them.

https://www.ebay.co.uk/itm/6CA7-EL34-EL34B-Sovtek-Fat-Electrically-Matched-Pair-New-Old-Stock-Valve-Tube/372152799486?epid=8010633289&hash=item56a60910fe:g:-5IAAOSwUn9aH-SQ:rk:2:pf:0

Edited by Hap Hazzard

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Thank you all for very speedy replies, and very sensible suggestions,  I must admit my personal choice would be the GEC 6CA7s which suit my musical taste very well, and I also hear a great deal about the KT77s, as for the 5881s, the reason I was asking is to ensure these are in fact compatible with the amplifier, and are not going to blow anything in use, is that the general opinion, that they can be used with out any further modification to the amp, my taste in music is mostly jazz and classical on vinyl if possible.

The system consists of the now classic Voyd/Helius/Goldring table, S500, Snell type K, Rotel and Sony CD players, Pure Tuner, Pioneer Ct91a cassette tape etc..., I also have Naim power/pre amps, Mission speakers, Yamaha tape recorder etc...

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1 hour ago, Juancho said:

Hi,
I've serviced /upgraded a dozen of these this year's I there's plenty out there! Clients split into three camps for valves: NOS which are expensive, 5881s which are very smooth across the range, and kt77s which offer a bit more punch across the range. I'd probably go with Genalex kt77s myself

David

Sent from my ONEPLUS A5000 using Tapatalk
 

Thank you for the reply, I just knew the Genalex KT77s would feature in this conversation, and I must admit I hear a great deal about these, all good, but where is best place to buy from, I am very tempted by the Black Treasure 6CA7s and hang the cost, anyone have experience with these tubes, they get very good reviews.!

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Super Dealer
1 hour ago, Redtube said:

Thank you all for very speedy replies, and very sensible suggestions,  , the reason I was asking is to ensure these are in fact compatible with the amplifier, and are not going to blow anything in use, is that the general opinion, that they can be used with out any further modification to the amp, my taste in music is mostly jazz and classical on vinyl if possible.

The system consists of the now classic Voyd/Helius/Goldring table, S500, Snell type K, Rotel and Sony CD players, Pure Tuner, Pioneer Ct91a cassette tape etc..., I also have Naim power/pre amps, Mission speakers, Yamaha tape recorder etc...

There is no problem with the Sovtek 5881s as direct replacements. I can't vouch for all other makes as many modern valves simply quote the original spec without actually meeting it

David

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This may help you with the ECC88s  sorry if it is a bit repetitive but copying a word document seemed to have had its problems :) 

·         6DJ8 / ECC88 is the "standard grade" of this family.  They normally have steel pins.

·         6922 / E88CC is a "premium grade" version of the 6DJ8.  Most have gold plated pins, but many Sylvania manufactured       6922's have steel pins (a few Sylvania's are gold pin). 

·         7308 / E188CC is generally the highest quality tube in the 6DJ8/ECC88 family.  Most have gold pins.  Sylvania's are steel pin.  They are designed with low microphonics and low noise.  Sections are usually pretty closely matched.

·         7DJ8 / PCC88  These are 7 volt filaments which were designed to be used in series string circuits.  However, they work well in standard 6DJ8 circuits and can generally be used as direct substitutes.  You can save some some money using these.

·         CCa  This is a special version of the 6922 / E88CC which is usually only found as Siemens or Telefunken.  These are very rare tubes

6DJ8 Description

6DJ8 was originally intended for RF cascode amplifier. The design targeted low noise, high conductance (gm), high mu and low internal resistance (rp).

In recent years, audio manufacturers realized this combination makes it perfect for audio application. We now have a wide variety of HiFi tube equipments with 6DJ8 type tubes on the market today.


6DJ8 family of tubes

Here are different numbers you see on 6DJ8 type tubes.

  • ECC88 is European numbering for 6DJ8.
  • 6922 is premium 6DJ8 type. E88CC is the European numbering for 6922. 
    6922 is slightly different, but is plug-in compatible with 6DJ8/ECC88 for all intent and purposes in audio gear.

Note: All of the 6DJ8/6922/ECC88/E88CC we carry are plug-in compatible where 6DJ8/6922 is called for.

  • 6N23P is the Russian 6922 and is also compatible with 6DJ8/6922. Electro-Harmonix 6922EH is derived from this 6N23P. The 6N23P family of tubes have relatively low microphony and noise. 6922EH is by far the best when it comes to low noise, and is recommended for phono or preamp application.
  • PCC88/7DJ8 has different heater, but close enough to make an excellent sub. They sound as good as their NOS 6DJ8 counterparts but at a lower price.
  • Russian 6N1P is similar to 6DJ8 and noted for being very linear. It can sub for 6DJ8, but check with your manufacturer first. 6N1P is sold under different brands, but they are made only by Voskhod factory in Russia with the Flying Rocket logo.

6DJ8 Selection Guide

  • For line stage and CD Player application where gain is low, any of the current production 6DJ8/6922, as well as NOS 6DJ8/6922 and even PCC88 tubes will work well.
  • In high gain application like phono or preamp, microphonics and noise become an issue. 
    Note that microphonics tends to be a problem for all 6DJ8 type tubes, including super expensive NOS 6DJ8 type tubes. The only exception isElectro-Harmonix 6922EH. If you intend to use 6DJ8/6922 in microphonic-sensitive application like phono stage, we recommend 6922EH

6N230 = 6922 = e88cc  And here is the final ranking! The point average across all songs to the right.

Reflektor Holy Grail '75 6N23P SWGP Silver Shields

121.7

Siemens Cca Gray Shield '63s

117.8

Siemen Cca Gray Shield '65s

117.5

Telefunken Ulm E188CC '60s

117.3

Reflektor '74 6N23P SWGP Silver Shields

116.1

Amperex PW D Getter

115.2

Philips Miniwatt SQ E188CC Herleen Halo Getter VR9 '64

114.2

Amperex USN-CEP 7308 White '65 VR5

113.7

Voskhod '75 6N23P Gray Shield SWGP

111.3

Amperex 7308 Green Print '68

109.1

Siemens E88CC '60s Gray

107.6

Telefunken Ulm E88CC '60s

107.5

Reflektor 6N23P '65 Dual Straight Wire Getter

106.8

Valvo Herleen E88CC '67 Large Halo Getter

106.3

Nevz 6N1P-E '66 

105.3

Siemens E88CC '70s Silver

100.0

Mullard England CV2492

94.6

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Super Wammer

I loved my S500 into Impulse H6's. Mine was converted to run triode at about 18w compared to pentode at 25w.  Would be sublime with original Snell K's. Contact Guy at Pure Sound for the info or David Wright then change the tubes based on their recommendations.

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8 hours ago, rabidlistener said:

My S500 runs 5881 valves and sounds really sweet.

Hey, am I correct that people are recommending the Solvtek 5881, as opposed to other makes or would others be just as suitable.?

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14 hours ago, yoda900 said:

I loved my S500 into Impulse H6's. Mine was converted to run triode at about 18w compared to pentode at 25w.  Would be sublime with original Snell K's. Contact Guy at Pure Sound for the info or David Wright then change the tubes based on their recommendations.

Hey thank you for reply, any idea how to get in touch with David Wright?

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Lovely sounding amp.:^

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1 hour ago, Tarzan said:

Lovely sounding amp.:^

Thank you that is very true, I like it very much, the only other amps I owned are the original Amplification and Recording A60, bought in 1980, for what was then an obscene amt of money, 190GBP, and that was an absolute peach of an amp, thgen a Naim Nac 45/Nap 90 combo which I still have, what can you say, a wonderful combo, but the S500 was a real revelation, with the Voyd/Snell is a gem, very few can compare, at any price in my view.

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Super Dealer

There's plenty of ways to make these amps even better. Have a look here for some ideas 

https://adaudioconsultants.wordpress.com

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