Problem with 610

[brandondrury]

Hey dudes,

A friend who is too busy producing a record right now to deal with a problem he is having with his preamp asked me to take care of it. I know very little about the technical side of tube preamps and I have a few questions.

I took the 610 back to my place. I mic'd up a bass with a 421. The preamp is very noisy and very distorted. I had to turn up the gain more than I expected as well.

I'm assuming that the tube is bad. This is what Mr. Producer thought too. How much does it cost to replace a tube in a 610? Is there any biasing necessary? Is this a simple swap or is there something more to it?

Thanks
Brandon Drury

 

[Plec]

Sounds like a typical tube issue. Take it to a tech and find out which tube you need to replace. Just like changing a light bulb, no biasing needed. Should cost something like 15$.

 

[neil wilkes]

Never liked those Sennheisers.
Great for Brass, but not much else.

Is the 421 set for music, and not speech? I assume it is.
Could well be the tube, could be something else like a bad lead - although this is unlikely.

How old is it?

 

[UAFanatic]

UA uses a great NOS 6072 but their 12ax7s are new JJs. The fault almost certainly is the JJ. Advice: get a really good NOS tube to replace it with and the 610 will sound just like it did back in the 60's.