[jamato8]

Here are the tubes. Obviously the GEC shown above are from China:

 

[AudioPowerHead]

Despite due diligence, this looks like a case where caveat emptor principle does not apply as the seller provided false information or misrepresented the product.

 

[jamato8]

Despite due diligence, this looks like a case where caveat emptor principle does not apply as the seller provided false information or misrepresented the product.

There is always a possibility that the Japanese seller did not know that they were fake. Check the holes in the plates and the lack of side getter. Also, they did not make them with a shiny metal base. It was always dull and there are a number of other things that are wrong with the Tubes.

 

[AudioPowerHead]

There is always a possibility that the Japanese seller did not know that they were fake. Check the holes in the plates and the lack of side getter. Also, they did not make them with a shiny metal base. It was always dull and there are a number of other things that are wrong with the Tubes.

You’re right. I believe even the Japanese seller has been fooled.

 

[AudioPowerHead]

Have a question on biasing. Is the ha-6a self-biasing or manual biasing ? Based on my reading, manual biasing is supposedly better in sound as it does not need bypass capacitors and the cathode is grounded through the bias meter. However, self-biasing is supposed to be better for tubes life span.

Right now, I am swooping tubes and just wondering if this topic matters at all for us who owns the ha-6a.

Would appreciate @Andykong or anyone who knows to kindly share. Thanks.

 

[Michaels1963]

Have a question on biasing. Is the ha-6a self-biasing or manual biasing ? Based on my reading, manual biasing is supposedly better in sound as it does not need bypass capacitors and the cathode is grounded through the bias meter. However, self-biasing is supposed to be better for tubes life span.

Right now, I am swooping tubes and just wondering if this topic matters at all for us who owns the ha-6a.

Would appreciate @Andykong or anyone who knows to kindly share. Thanks.

I was just thinking the same question. I don't find any information on the biasing of the HA-6A anywhere that I have looked I hope someone knows

 

[Andykong]

Have a question on biasing. Is the ha-6a self-biasing or manual biasing ? Based on my reading, manual biasing is supposedly better in sound as it does not need bypass capacitors and the cathode is grounded through the bias meter. However, self-biasing is supposed to be better for tubes life span.

Right now, I am swooping tubes and just wondering if this topic matters at all for us who owns the ha-6a.

Would appreciate @Andykong or anyone who knows to kindly share. Thanks.

HA-6A is auto-bias

 

[AudioPowerHead]

HA-6A is auto-bias

Cool. Thanks Andy !

 

[Michaels1963]

I tried the GE Rectifier tubes 22DE4 I don't hear any difference over the stock RCA rectifier tubes. Do you hear any difference in rectifier tubes I find more on Ebay don't know if there worth the time

 

[AudioPowerHead]

I tried the GE Rectifier tubes 22DE4 I don't hear any difference over the stock RCA rectifier tubes. Do you hear any difference in rectifier tubes I find more on Ebay don't know if there worth the time

Not tried it yet although I believe there could be some degree of audio benefits with the right tubes installed based on what has been shared by others in Cayin threads.

I think more remarkable tonal alterations and sonic nuances could be derived from pre-amp input and power tubes.

 

[Michaels1963]

Not tried it yet although I believe there could be some degree of audio benefits with the right tubes installed based on what has been shared by others in Cayin threads.

I think more remarkable tonal alterations and sonic nuances could be derived from pre-amp input and power tubes.

I already tube roll the Pre and Power tubes thought I would try the Rectifier Tubes Now

 

[Andykong]

May I know the Cayin contact you discussed regarding using E80CC in HA-6A? This goes against our recommendation directly. I would like to clarify that ECC80 is not a direct replacement for EDD82, it can't be used in HA-6A.

In fact, I have responded to another query through PM last month and I used almost the exact wording to response to the same issue. I hope I can get in touch with your Cayin contact and clarify his/her mistake regarding using ECC80 in HA-6A.

Since there are mixed responses regarding E80CC, we had a thorough discussion regarding the technical feasibility of this vacuum tube as a replacement for 12AU7 on our vacuum tube headphone amplifiers. After checking the specification in detail, Chen DeHai, our Chief Engineer confirmed that E80CC can be used in HA-6A and HA-3A. The E80CC will draw more heater current, which might affect the long terms tear and wear of the amplifier slightly, but it is technically safe in HA-6A and HA-3A, it won't blow the amplifier or damage the transformers.

We won't add E80CC to the recommended tube replacement table in our product manual. In our past experience, this will introduce a misunderstanding that E80CC is a direct replacement of 12AU7 and can be used as a replacement in all other tube amplifiers (including speaker amplifiers) when they can't find any reference to E80CC in their product manual.

Sorry for the miscommunication in the past, we hope this will clarify the situation.

 

[shafat777]

Since there are mixed responses regarding E80CC, we had a thorough discussion regarding the technical feasibility of this vacuum tube as a replacement for 12AU7 on our vacuum tube headphone amplifiers. After checking the specification in detail, Chen DeHai, our Chief Engineer confirmed that E80CC can be used in HA-6A and HA-3A. The E80CC will draw more heater current, which might affect the long terms tear and wear of the amplifier slightly, but it is technically safe in HA-6A and HA-3A, it won't blow the amplifier or damage the transformers.

We won't add E80CC to the recommended tube replacement table in our product manual. In our past experience, this will introduce a misunderstanding that E80CC is a direct replacement of 12AU7 and can be used as a replacement in all other tube amplifiers (including speaker amplifiers) when they can't find any reference to E80CC in their product manual.

Sorry for the miscommunication in the past, we hope this will clarify the situation.

Thank you Andy for the clarification, its really helpful to finally erase any form of doubt regarding this issue and now we can all go back to enjoying this wonderful amp.

 

[krude]

Since there are mixed responses regarding E80CC, we had a thorough discussion regarding the technical feasibility of this vacuum tube as a replacement for 12AU7 on our vacuum tube headphone amplifiers. After checking the specification in detail, Chen DeHai, our Chief Engineer confirmed that E80CC can be used in HA-6A and HA-3A. The E80CC will draw more heater current, which might affect the long terms tear and wear of the amplifier slightly, but it is technically safe in HA-6A and HA-3A, it won't blow the amplifier or damage the transformers.

We won't add E80CC to the recommended tube replacement table in our product manual. In our past experience, this will introduce a misunderstanding that E80CC is a direct replacement of 12AU7 and can be used as a replacement in all other tube amplifiers (including speaker amplifiers) when they can't find any reference to E80CC in their product manual.

Sorry for the miscommunication in the past, we hope this will clarify the situation.

Kudos. I really appreciate your efforts in providing support. You're doing an amazing job here.

 

[lightoflight]

The Tungsram E80CC is great with TS EL34. Yet to try it with EH EL34 but I suspect it will be a great combination as well.