Tubes Asylum

Which 5AR4 is best for Bass.. Ruby, Sovtek, Sino, Valv Art, etc.

141.156.18.152

[ Follow Ups ] [ Post Followup ] [ Thread: Display Email Next ] [ Tubes Asylum ]

Marc L.

(A)

I am bi-amping my speakers.
The top two amps drive the electrostatic panels of my ReQuest speakers (180hz on up). I am using Mullard CV378 rectifiers in that pair.

I am looking for the best new production 5AR4 rectifiers to use in the bottom two amps, which will drive the woofers of my ML ReQuest speakers and also send signal to my Velodyne fsr-15 subwoofer (plays flat to at least 20hz) via the speaker level inputs. Since they only have to drive the woofers to about 180hz and also since they will need to be strong down to 20hz, I am interested in which 5AR4 tubes have the best bass.
Any recommendations?
Thanks!
Marc.

Follow Ups:

Re: Which 5AR4 is best for Bass.. Ruby, Sovtek, Sino, Valv Art, etc. - Joelt 12:19:47 09/10/03 (1)
Marc,
It's a very simple test to see if your amps are up to the task at hand or not. Simply hook them up to a scope and simple function generator, and see if they can deliver their rated power at 20Hz. If they can, then the PSU is adequate as is.
If not, (3dB or more down at 20Hz, ugly square waves, etc), then start to look at improvements - REAL improvements with MEASURABLE benefits such as: increasing the PSU capacitance, lowering the PSU output impedance, lowering the PSU DCR, etc.
Fixes like these will be audible and cost a lot less than a Mullard GZ34.
Joel
- Re: Which 5AR4 is best for Bass.. Ruby, Sovtek, Sino, Valv Art, etc. - dave slagle 17:49:12 09/10/03 (0)
  if being -3db at 20 hz is due to anything other than the output trannie through intentional design you got problems...
  dave
Another idea - Bob Samuelson 11:38:51 09/10/03 (2)
If your power supply capacitance and voltage rating thereof are up to it then you'll probably get the best bass performance out of diodes. You can leave the 5AR4 in place and wire the diodes to the tube socket. You may also need a resistor to drop the voltage a bit. The 5AR4 still glows real pretty yet you have a little better bass control with the diodes. Just for the record, I don't biamp so I've never tried it. Let the flames begin.
Bob
- Re: Another idea - steve oda 17:38:24 09/10/03 (1)
  Bob,
  Agree with you---the best for bass is an SS diode bridge. No sag. Go to 1N5408's for even more PIV and current. You may need to use greater resistance in the voltage dropping resistors to keep the gain stage and phase inverter in the manufacturer's recommended plate voltage region.
  You can also experiment with slightly larger capacitance and voltage ratings in the pi-filter to give you more reserve power and tighter bass.
  - Re: Another idea - radioactive 21:41:12 09/10/03 (0)
    if you dont feel like soldering you could always use a solid state rectifier replacement that plugs into the socket.
    chris
    http://groovetubes.com/product.cfm?Product_ID=1647
    by the way i have no affiliation with groove tubes whatsoever just trying to show another alternative to sodering diodes under the amp
Re: Which 5AR4 is best for Bass.. Ruby, Sovtek, Sino, Valv Art, etc. - vrogers3 11:12:35 09/10/03 (1)
In my system the differences between 5AR4's typically are from 20Hz-20kHz. If they're weak on the bottom they are thin in the midrange and tinny on the top as well.
Using the venerable Mullard as a reference, I find the latest Sovtek and JJ's to be very close - but I haven't used them long enough to comment on reliability. I had a lot of Chinese 5AR4's blow up on me, so I stopped using them. I've read that their high failure rate is closely associated with Dynaco equipment - I don't know the details.
IMHO the JJ's and Sovtec are so close not only to the Mullard but to each other, that any future purchases I make will be based on reliability. I think most of the current 5AR4's have come a long way in terms of sound quality - and getting somewhat better in regards to reliability.
- Re: Which 5AR4 is best for Bass.. Ruby, Sovtek, Sino, Valv Art, etc. - NOS440 19:24:28 09/10/03 (0)
  I've put the Sovtek and the JJ's thru the ringer with 120uF right on the rectifier output and they have held up for months & months in my own personal amps. If you want your amps to produce more bass beef up the filtering on the first stage to about 80uf and 200uF on the center tap. Works like a charm ! Its not as tight a bass as SS rectifiers can provide but you still retain the wonderful tube rectifier sound and your tubes won't suffer from cathode stripping. Just keep spare tubes around incase one does start arching what the heck for $12 each although I have yet to get one to do it.
  Note because of reliabilty I do not beef up the first stage beyond 60uF for my customers !
  Craig Ostby
  www.NOSValves.com

This post is made possible by the generous support of people like you and our sponsors:

VH Audio

You can not post to an archived thread.