Does this amp have a problem or is it OK to buy?


I'm considering a Jolida 302B. Having seen reports of humming trannies, I asked the seller about it. His response is below. I don't know if this is a problem or normal. Even if slightly wrong, I'd rather not buy. What do you think?
"With the speakers connected to the 302B, I can hear a very faint hum from the speakers, but you have to put your ear right against the speaker grill to hear the hum. Turning the volume knob on the 302B has no effect on the amount of hum - the sound level remains constant regardless of the volume setting. Again, I must stress that the volume of hum is so slight, I doubt if anyone in a silent room will notice it, even when standing close to it. You really have to put your ear against the speaker to hear the very faint hum. I believe this kind of hum is generated by all amplifiers - try listening to your current amp. When listening to music, I doubt if one can hear the effects of it even in quiet passages.

Now, with a CD player hooked up to the Jolida, the hum level increases as you increase the volume on 302B. When the volume dial is turned down to minimum, the level of hum is very faint (same level as if cd player was not connected). When the volume is turned to MAXIMUM, the hum becomes noticeable as you approach the speaker (about 3 feet away). In addition, when the CD player is on, and the input selector on the 302B is set to other than CD (such as AUX), turning the volume knob has no bearing on the hum level - it stays constant at the barely audible level. I believe what this indicates is that by itself, the 302B is very quiet (just a barely audible hum), and when you hook up a CD player or phono stage, the inherent noise (hum) from those external sources are magnified as you increase the volume. "

Thanks....
river251
It might be normal for Jolida but I would stand clear of it. Humming bothers me and I won't stand for it. To me an amp humming has no place in high end audio.
Having seen reports of humming trannies

Mechanical vibrating noise from the transformer itself.

All transformers hum to some degree.

What the seller describes in his reply has nothing to do with transformer mechanical humming noise.

Also I would add what the seller describes in his response would be normal in many audio systems if the sound he is hearing is actually white noise and not humming.
Try his test on your existing audio system......

Email the seller back and explain to him what you want to know is if he can hear the power transformer humming with his ears, say, 3 ft from the amp.

Also ask him about his test.... Was the sound he was describing, with the volume cranked up all the way, hum or white noise?

"With the speakers connected to the 302B, I can hear a very faint hum from the speakers, but you have to put your ear right against the speaker grill to hear the hum. Turning the volume knob on the 302B has no effect on the amount of hum - the sound level remains constant regardless of the volume setting. Again, I must stress that the volume of hum is so slight, I doubt if anyone in a silent room will notice it, even when standing close to it.

Now, with a CD player hooked up to the Jolida, the hum level increases as you increase the volume on 302B. When the volume dial is turned down to minimum, the level of hum is very faint (same level as if cd player was not connected).

When the volume is turned to MAXIMUM, the hum becomes noticeable as you approach the speaker (about 3 feet away). In addition, when the CD player is on, and the input selector on the 302B is set to other than CD (such as AUX), turning the volume knob has no bearing on the hum level - it stays constant at the barely audible level.

Just bet the seller is confusing white noise with hum.....

.
If you hear the hum or buzz through the woofer, then I would stay away as it is not simply tube hiss etc....
Remember hum through the speakers can be caused by cable tv issues, interconnects etc. or other external issues that have nothing to do with the amp itself. Also, if there is a bit of hum through the speakers, and it is amp related, the loudness of the hum will also be a function of the sensitivity of the speaker. If your speakers are more efficient than the owners the hum could be louder. How old is this amplifier?
Humming to the speakers is because the AC filament supply to the 12AU7 is making it into a buzzy microphone.

Spent MONTHS on my previously modded 302B to fix the problem by taking out the center tap for the filament which had become intermittent, and building a 100Ohm--100Ohm center tap, and elevating the filament center to about 70V.

Most modders who know about filament elevation for SRPP gain stages would know how to do this.