Need help. I was wondering if someone could tell me if I can swap the Sovtek 5AR4 tubes in this pre amp for Sophia Electric Princess 274B mesh plates. Thx
https://cayin.com/produkt/cayin-sc-10/
https://cayin.com/produkt/cayin-sc-10/
As far as I know, the Sophia 274B is normally a direct substitute. However, your Cayin may have a too big first cap in the power supply for reliable operation of the 274B. Impossible to tell without schematic. Many Chinese tube preamps/amps have a huge first cap.
Check physical dimensions as well. I suppose that the 274B is a lot larger than the 5AR4.
Check physical dimensions as well. I suppose that the 274B is a lot larger than the 5AR4.
Thx for the response. Yes I know physically they are bigger, thats ok though. You are right I need to check what size first caps are in there. Do you have any idea up to what size they should be?
Thx, yes I know they are physically bigger, but that's ok. Do you know up to what size the first cap should be?
Why are you considering this ?
Do you expect B+ from a different rectifier be different ? Or do you
simply have an excess of money to burn ?
In sweden we say that using a sailboat is equally fun as thrashing large
banknotes while standing naked in an ice-cold shower.
Interresting saying Peter. It is safe to say that it would never cross the mind of anyone in southern europe. 😉
That said, from my limited experience, amplifiers that are 'enhanced' with a different rectifier suffer from design weaknesses. Maybe the 'enhancement' is only percieved.
Ian
That said, from my limited experience, amplifiers that are 'enhanced' with a different rectifier suffer from design weaknesses. Maybe the 'enhancement' is only percieved.
Ian
Very interesting saying Peter. No don't have money to burn. I will try the amplifier as is first then make my decision. I only asked because someone has the same pre amp but the factory released it with the 274B but not sure if any other changes were made for these different tubes.
Regarding the first cap according to Sophia Electric:
Note(*): 274B is direct heating tube. The indirect heating 5AR4 may turn on slower, however, people who buy 274B is for its superior sonic performance. To fully utilize its benefits, it may require first stage capacitor (capacitor input) to be less than 10MFD, or would shorten the 274B life span (very much like smoking is bad for your health). It would not be a problem with common choke input. Please consult to your amplifier maker or refer to a tube manual. This 274B is an update of the NOS WE 274B, so both share with same characters. In 1930s, WE 274B was the rectifier choice for 300B single ended theater amplifier in the US.
The maximum current capability for Sophia Electric 274B mesh plate tube is 90ma, suitable for tube pre-amp and mono-block 45 single ended and 2A3 mono-block single ended.
Note(*): 274B is direct heating tube. The indirect heating 5AR4 may turn on slower, however, people who buy 274B is for its superior sonic performance. To fully utilize its benefits, it may require first stage capacitor (capacitor input) to be less than 10MFD, or would shorten the 274B life span (very much like smoking is bad for your health). It would not be a problem with common choke input. Please consult to your amplifier maker or refer to a tube manual. This 274B is an update of the NOS WE 274B, so both share with same characters. In 1930s, WE 274B was the rectifier choice for 300B single ended theater amplifier in the US.
The maximum current capability for Sophia Electric 274B mesh plate tube is 90ma, suitable for tube pre-amp and mono-block 45 single ended and 2A3 mono-block single ended.
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