Search Buy Sell Learn MyPage
 Learn > Forums > Amps Preamps > 1258431143  Start New Thread | Log In | Bookmark This

  looking for a good bass tube preamp
Hello all,

I am looking for a tube preamp with good bass reproduction. My power amp is Krell KSA250 and budget is about $1000. Any suggestion? Thanks!
Toebi  (Threads | Answers | This Thread)

11-19-09: Toebi
Is my budget too low?
Toebi  (Threads | Answers | This Thread)

11-19-09: Dob
Used Joule-Electra preamps. Best bass around - read Harry Pearson of TAS review on their web site.


Dob  (Reviews | Threads | Answers | This Thread)

11-19-09: Rotarius
Audio electronics ae-3 mkII
Rotarius  (Threads | Answers | This Thread)

11-19-09: Bob_reynolds
The bass response with a tube preamp depends on the output impedance of the preamp and the input impedance of the connected amp. Using the worst case output impedance (not the manufacturer's "nominal" value) with the 10X impedance matching rule of thumb is usually acceptable. Some people suggest a ratio of 20X or more.

I don't know why cost would be a factor. If the input impedance of your amp is sufficiently high, then you'll have many choices. So determine the input impedance of your amp, divide that by 10 and look for preamps whose worst case output impedance does not exceed that value.

The Stereophile web site is a good resource for this type of information. The Audio Research SP16 has a low output impedance and should work well with solid state amps.

Bob_reynolds  (Threads | Answers | This Thread)

11-19-09: Koven
hey bob, so with an input impedance of 20k on the power amp.... you're saying 2k output impedance is the highest acceptable output for the preamp?
Koven  (Threads | Answers | This Thread)

11-19-09: Toebi
My power amp input impedance is 47k, so the output impedance of preamp should be 4.7k or less. Am I right? Thanks!
Toebi  (Threads | Answers | This Thread)

11-19-09: Ajackson1
Toebi yes with a 47k input imp u can go 4700 ohms output imp worst case on the pre. The lower the output imp on the pre the better.
Ajackson1  (System | Threads | Answers | This Thread)

11-20-09: Bob_reynolds
Koven, yes, as Ajackson1 said. The trick is determining the worst case output impedance and at what frequency.
Bob_reynolds  (Threads | Answers | This Thread)

  Post your response

Your response

No html, but you may use markup tags

Members only