EL34 or KT 88

Dr Sarkar

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Hello! I have a Dared MP 60 integrated tube amp. I am contemplating to change the 4 stock EL34 tubes. Are EL34 and KT 88 tubes interchangeable? If yes what’s the sonic difference between the two? And finally how to procure them in India ? My primary preference in music is Indian classical instrumental and vocal. Regards
 

mbhangui

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Hello! I have a Dared MP 60 integrated tube amp. I am contemplating to change the 4 stock EL34 tubes. Are EL34 and KT 88 tubes interchangeable? If yes what’s the sonic difference between the two? And finally how to procure them in India ? My primary preference in music is Indian classical instrumental and vocal. Regards
They are interchangeable. I replaced my EL34 with Golden Lion KT88. The HF portion is much better in the KT88. Got it from Amazon.com.

EDIT:
Sorry disregard my comment. It was KT77 that I repaced my EL34.
 

arj

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What are the stock tubes. ? Rather than changing to a KT88/77 why dont you try and get a nice Mullard or JJ El34 first ?
Stock tubes are usually Sovtek and they are not the most musical.

Unfortunately you need to import it...

a noce discussion on the difference Here
 

Dr Sarkar

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What are the stock tubes. ? Rather than changing to a KT88/77 why dont you try and get a nice Mullard or JJ El34 first ?
Stock tubes are usually Sovtek and they are not the most musical.

Unfortunately you need to import it...

a noce discussion on the difference Here
Thanks for the response. No brand is as such mentioned on the tubes. Planning to go for JJ only but read about the enhanced lower frequency quality with KT 88 hence the state of confusion. I’ll go through the forum link. Regards
 

[email protected]

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Agree with arj. Rather than changing tube topology which often requires bias adjustment to sound the best , it’s better to get a different brand of the default tubes. Mullards should be a very nice replacement provided you get genuine ones.Telefunkens are a bit clinical but also a good option
 

Dr Sarkar

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Agree with arj. Rather than changing tube topology which often requires bias adjustment to sound the best , it’s better to get a different brand of the default tubes. Mullards should be a very nice replacement provided you get genuine ones.Telefunkens are a bit clinical but also a good option
Problem is the genuine source
 

coaltrain

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Hello! I have a Dared MP 60 integrated tube amp. I am contemplating to change the 4 stock EL34 tubes. Are EL34 and KT 88 tubes interchangeable? If yes what’s the sonic difference between the two? And finally how to procure them in India ? My primary preference in music is Indian classical instrumental and vocal. Regards

Some points to consider:

- The KT88 is not a drop in replacement for the EL34. The 6CA7 and KT77 are. The KT88 will demand more from your amp, so please check your owner’s manual to make sure it’s safe.
- EL34s have a warmer midrange, KT88s have better bass and treble. Given your choice of music, the EL34 may actually be better for you.
- You may actually get a bigger improvement in SQ by swapping out the preamp tubes. Your amp probably runs 12AX7s, 12AU7s, 6SN7s, 6SL7s, or some combination thereof. These are cheaper to replace and easier to find.
- If your amp is Chinese, the stock tubes are probably Shuguong. If it’s American or European, it’s probably EH, Sovtek or JJ. The Shuguong power tubes are pretty good, the preamp tubes are not. No personal experience with JJ, but some people don’t find them very reliable.
- If you swap out the power tubes, make sure you get a matched quad. Not easy finding NOS quads that are matched. Also, is your amp auto biasing? If not, check how you’re going to bias the new power tubes. Preamp tubes don’t need biasing.
- For NOS tubes, check out audiotubes.com. For new tubes (Russian, Chinese or Slovakian), check out thetubestore.com. In India, check out audionote.in.

Hope that helps, and happy tube rolling :)
 

muralimmreddy

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Dr Sarkar

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Some points to consider:

- The KT88 is not a drop in replacement for the EL34. The 6CA7 and KT77 are. The KT88 will demand more from your amp, so please check your owner’s manual to make sure it’s safe.
- EL34s have a warmer midrange, KT88s have better bass and treble. Given your choice of music, the EL34 may actually be better for you.
- You may actually get a bigger improvement in SQ by swapping out the preamp tubes. Your amp probably runs 12AX7s, 12AU7s, 6SN7s, 6SL7s, or some combination thereof. These are cheaper to replace and easier to find.
- If your amp is Chinese, the stock tubes are probably Shuguong. If it’s American or European, it’s probably EH, Sovtek or JJ. The Shuguong power tubes are pretty good, the preamp tubes are not. No personal experience with JJ, but some people don’t find them very reliable.
- If you swap out the power tubes, make sure you get a matched quad. Not easy finding NOS quads that are matched. Also, is your amp auto biasing? If not, check how you’re going to bias the new power tubes. Preamp tubes don’t need biasing.
- For NOS tubes, check out audiotubes.com. For new tubes (Russian, Chinese or Slovakian), check out thetubestore.com. In India, check out audionote.in.

Hope that helps, and happy tube rolling :)
Thanks a ton for the very informative post.
Some points to consider:

- The KT88 is not a drop in replacement for the EL34. The 6CA7 and KT77 are. The KT88 will demand more from your amp, so please check your owner’s manual to make sure it’s safe.
- EL34s have a warmer midrange, KT88s have better bass and treble. Given your choice of music, the EL34 may actually be better for you.
- You may actually get a bigger improvement in SQ by swapping out the preamp tubes. Your amp probably runs 12AX7s, 12AU7s, 6SN7s, 6SL7s, or some combination thereof. These are cheaper to replace and easier to find.
- If your amp is Chinese, the stock tubes are probably Shuguong. If it’s American or European, it’s probably EH, Sovtek or JJ. The Shuguong power tubes are pretty good, the preamp tubes are not. No personal experience with JJ, but some people don’t find them very reliable.
- If you swap out the power tubes, make sure you get a matched quad. Not easy finding NOS quads that are matched. Also, is your amp auto biasing? If not, check how you’re going to bias the new power tubes. Preamp tubes don’t need biasing.
- For NOS tubes, check out audiotubes.com. For new tubes (Russian, Chinese or Slovakian), check out thetubestore.com. In India, check out audionote.in.

Hope that helps, and happy tube rolling :)
thanks a ton for the informative post. My tube amp is Chinese. I’ll try to find the preamp tubes too for swapping. Regards
 

Yelamanchili manohar

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Some points to consider:

- The KT88 is not a drop in replacement for the EL34. The 6CA7 and KT77 are. The KT88 will demand more from your amp, so please check your owner’s manual to make sure it’s safe.
- EL34s have a warmer midrange, KT88s have better bass and treble. Given your choice of music, the EL34 may actually be better for you.
- You may actually get a bigger improvement in SQ by swapping out the preamp tubes. Your amp probably runs 12AX7s, 12AU7s, 6SN7s, 6SL7s, or some combination thereof. These are cheaper to replace and easier to find.
- If your amp is Chinese, the stock tubes are probably Shuguong. If it’s American or European, it’s probably EH, Sovtek or JJ. The Shuguong power tubes are pretty good, the preamp tubes are not. No personal experience with JJ, but some people don’t find them very reliable.
- If you swap out the power tubes, make sure you get a matched quad. Not easy finding NOS quads that are matched. Also, is your amp auto biasing? If not, check how you’re going to bias the new power tubes. Preamp tubes don’t need biasing.
- For NOS tubes, check out audiotubes.com. For new tubes (Russian, Chinese or Slovakian), check out thetubestore.com. In India, check out audionote.in.

Hope that helps, and happy tube rolling :)
Very well put across @coaltrain
and covered everything very well :)

I will just add that EL34 and KT88 need different bias voltages. So unless the amp is self biasing, which I really doubt, it will be a non starter to replace the tubes. As the bias voltage of KT88 is close to twice of the EL34, depending on the implementation of the circuit.

@Dr Sarkar please see if you can find the manufacturers literature for bias settings for different tube types.

I found big changes by changing the input tubes. And this needs no bias changes. I replaced a EH 12AU7 with a gold lion I got from amazon, and it was a immediate improvement in transparency.

KT88 are high power output tubes, of course there are higher power KT120 and KT150 tubes out there. I found KT88's with a high negative feed back sound like class A amps, and the tube magic aka the pleasant distortion vanishes. They have solid bass and extend well into the treble. Listening blind, I could swear it was a class A SS amp playing.

EL34's by comparison drop the power to 70% of the output achievable with KT88. They do mid range beautifully. Probably beaten only by the 300B and 2A3 tubes. But they roll of both the treble and bass noticably. The bass extension as well as control is reduced. But I feel the EL34 will compliment your musical tastes better than the KT88. Just my 2 cents :)

P.S : though the amplification is done by the tubes. The amp circuit has to provide a higher grid voltage as we replace the output tubes with a higher power tube. This will stress the circuit. This might increase the THD of the amp. Thus it is safer to replace a higher output tube with a lower output tube, than doing vice versa. So if your amp originally came with EL34 tubes, then maybe best to stick with them, unless you can find some posts on the net, where someone has already done this with superior results. All the best :)
 

Analogous

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@Dr Sarkar, the stock tubes in the Dared MP60 are Shugang.

Here is a thread that discusses tube rolling on this amp: https://www.audioasylum.com/cgi/t.mpl?f=tubes&m=214898

I am waiting on a delivery of a Tesla NOS tube from a supplier who is considered reliable, from Germany.
The cost of one tube including shipping was 17,500/-. I don’t know what the customs duty will be yet.

One cheaper alternative to consider are replacing the 12AX7s with a pair of NOS Trigons, which are re-labeled BEL (Bharat Electronics, LTD.) 12AX7s, which are said to be identical to Mullards, as Mullard/Phillips helped set up the BEL factory with Phillips machinery. I have not heard these and FM with experience using BEL tubes may be able to share their insights on these.
 
Last edited:

arj

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- You may actually get a bigger improvement in SQ by swapping out the preamp tubes. Your amp probably runs 12AX7s, 12AU7s, 6SN7s, 6SL7s, or some combination thereof. These are cheaper to replace and easier to find.

On the leben CS 600 the preamp tubes dod not make much of a difference but the power tubes did..so I guess its amp design specific. agree with your other point . I would be surprised if the tubes are Shuguang. in order to keep process low they go for the cheapest ones so both Pre and power might benefit from a change.

The JJ 12AX7 and EL34 are usually the most cost effective and available and yes the extra you pay for a matched quad is worth it.

Tubedepot.com is a good option to buy from.
 

Dr Sarkar

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Th
Very well put across @coaltrain
and covered everything very well :)

I will just add that EL34 and KT88 need different bias voltages. So unless the amp is self biasing, which I really doubt, it will be a non starter to replace the tubes. As the bias voltage of KT88 is close to twice of the EL34, depending on the implementation of the circuit.

@Dr Sarkar please see if you can find the manufacturers literature for bias settings for different tube types.

I found big changes by changing the input tubes. And this needs no bias changes. I replaced a EH 12AU7 with a gold lion I got from amazon, and it was a immediate improvement in transparency.

KT88 are high power output tubes, of course there are higher power KT120 and KT150 tubes out there. I found KT88's with a high negative feed back sound like class A amps, and the tube magic aka the pleasant distortion vanishes. They have solid bass and extend well into the treble. Listening blind, I could swear it was a class A SS amp playing.

EL34's by comparison drop the power to 70% of the output achievable with KT88. They do mid range beautifully. Probably beaten only by the 300B and 2A3 tubes. But they roll of both the treble and bass noticably. The bass extension as well as control is reduced. But I feel the EL34 will compliment your musical tastes better than the KT88. Just my 2 cents :)

P.S : though the amplification is done by the tubes. The amp circuit has to provide a higher grid voltage as we replace the output tubes with a higher power tube. This will stress the circuit. This might increase the THD of the amp. Thus it is safer to replace a higher output tube with a lower output tube, than doing vice versa. So if your amp originally came with EL34 tubes, then maybe best to stick with them, unless you can find some posts on the net, where someone has already done this with superior results. All the best :)
Thank you for the very elaborate explanation. I appreciate.
 

Dr Sarkar

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On the leben CS 600 the preamp tubes dod not make much of a difference but the power tubes did..so I guess its amp design specific. agree with your other point . I would be surprised if the tubes are Shuguang. in order to keep process low they go for the cheapest ones so both Pre and power might benefit from a change.

The JJ 12AX7 and EL34 are usually the most cost effective and available and yes the extra you pay for a matched quad is worth it.

Tubedepot.com is a good option to buy from.
On the leben CS 600 the preamp tubes dod not make much of a difference but the power tubes did..so I guess its amp design specific. agree with your other point . I would be surprised if the tubes are Shuguang. in order to keep process low they go for the cheapest ones so both Pre and power might benefit from a change.

The JJ 12AX7 and EL34 are usually the most cost effective and available and yes the extra you pay for a matched quad is worth it.

Tubedepot.com is a good option to buy from.
Here is the details of my amp.
 

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Dr Sarkar

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@Dr Sarkar, the stock tubes in the Dared MP60 are Shugang.

Here is a thread that discusses tube rolling on this amp: https://www.audioasylum.com/cgi/t.mpl?f=tubes&m=214898

I am waiting on a delivery of a Tesla NOS tube from a supplier who is considered reliable, from Germany.
The cost of one tube including shipping was 17,500/-. I don’t know what the customs duty will be yet.

One cheaper alternative to consider are replacing the 12AX7s with a pair of NOS Trigons, which are re-labeled BEL (Bharat Electronics, LTD.) 12AX7s, which are said to be identical to Mullards, as Mullard/Phillips helped set up the BEL factory with Phillips machinery. I have not heard these and FM with experience using BEL tubes may be able to share their insights on these.
Thank you sir for the lead
 

coaltrain

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My tube amp is Chinese

The three major tube manufacturers today are New Sensor (Russia), Shuguang (China) and JJ (Slovakia). Almost every amp made in China, from the cheaper Reisongs to the more expensive Primalunas, uses Shuguang tubes. With varying levels of QC, of course.
Psvane is another Chinese tube maker, basically a bunch of guys who left Shuguang and set up their own shop. Their tubes are supposedly more high end, though I’m yet to try them.

You can check out the Chinese tubes here:

Also, you might find this video helpful if you get the urge to splurge :)

 

Dr Sarkar

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The three major tube manufacturers today are New Sensor (Russia), Shuguang (China) and JJ (Slovakia). Almost every amp made in China, from the cheaper Reisongs to the more expensive Primalunas, uses Shuguang tubes. With varying levels of QC, of course.
Psvane is another Chinese tube maker, basically a bunch of guys who left Shuguang and set up their own shop. Their tubes are supposedly more high end, though I’m yet to try them.

You can check out the Chinese tubes here:

Also, you might find this video helpful if you get the urge to splurge :)

I have got my hands on some new Cayin spark EL34, EH 12AX7 tubes. Price negotiation is on. How is Electro harmonix as tubes ?
 

coaltrain

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Cayin will also be Shuguang, so not much different from what you currently have.
EH, Genalex Gold Lion and Sovtek are all made in the same factory - Reflektor in Russia. Very minor differences between the three and they’re all pretty decent.
 
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