1. Home
  2. speakers
  3. 1156703028

Low watt tube amps/pros/cons

300B's, 845's and others. What are some of the benifits of these tubes as well as the limitations. I see someone posted that he has a 15 watt tube amp and wants to get 30hz bass. It is highly unlikely that his amp will deliver as low as 30hz, even if he did find a speaker that went to that level, would the bass have any authority? Also by saying I want to find a speaker that goes to 30hz hows the mids anf highs. IOW I'd never buy any speaker based on the fact that it goes to 25hz, its a package deal.
Back to the main idea here. Can anyone give a list of +'s and the ='s of the low watt tube amps. For myself its not something I'm interested in as all my listenings are classical, and I want the orchestras to sound full rich, dynamic, that is the low and high end extended. I heard a 300B amp, the Cayin, and was incredible with light jazz, blues, but for classical orchestral it fell flat and lifeless. The speakers were the Silverline Sonatas.
bartokfan
reubent
3,587 posts
 
Duke,

Can you recommend any freeware loudspeaker modeling programs? I have a pair of Hemp Acoustics FR8.0DIY drives currently installing is a cabinet that was not really designed for them.

I know the manufacturer recommends an 85 liter vented box whch places the center of the driver at about ear height. He also recommends side venting with a 4" port that is 3" long.

Any suggestions for a program that will do a simple bass reflex cabinet?

Thanks,

TIC
audiokinesis
1,872 posts
 
Hi Reubent,

Here's a pretty good freeware program. The vent length calculations aren't totally reliable. Box stuffing isn't accounted for, nor is enclosure wall losses, but this will get you in the ballpark:

http://www.ggimages.com/spsim/

In practice, expect that a vent slightly shorter than recommended will give the proper tuning frequency. It takes a pretty sophisticated program to properly account for the fluid flow dynamics at the ends of the vent (even if you use a flared port).

Enjoy!

Duke
reubent
3,587 posts
 
Thanks Duke!

TIC
porziob
316 posts
 
These 300B & 845 SETs act as tone controls, & most are deficient in the bass & topend.
herman
1,974 posts
 
These 300B & 845 SETs act as tone controls, & most are deficient in the bass & topend.

Attributing this to the tube is simply wrong. It comes from misinformed individuals who don't understand electronics especially the interaction of amps and speakers.

Amps that use these tubes are often paired with incompatible speakers and the combination can be deficient in the bass & top end. They are sometimes used in amps of poor design or that have poor output transformers. However, the tubes are capable of amplifying from near DC to way beyond what is audible. Used in a well designed amplifier they are not the limiting factor.
More to discover