Welcome, Guest. Please Login or Register
Decware Audio Forums
03/28/24 at 17:28:04 




Pages: 1
Send Topic Print
Experience using 807 tube (Read 1001 times)
safebelayer
Seasoned Member
****




Posts: 200
Experience using 807 tube
03/13/23 at 00:14:17
 
I just installed some RCA 807s in my mkiv. All but one tube transmits sound to my speakers when I tap on them. I have not had this experience with 6L6, 7581a, EL34, or 6p3s tubes.

Does anyone have any experience with this tube in their mkiv?

Thank you
Back to top
 
 
  IP Logged
jec3504
Ex Member



Re: Experience using 807 tube
Reply #1 - 03/13/23 at 03:14:36
 
safebelayer,

From your description sounds like the tubes went microphonic.
Back to top
 
 
  IP Logged
Rivieraranch
Seasoned Member
****




Posts: 2126
Re: Experience using 807 tube
Reply #2 - 03/13/23 at 05:14:14
 
When I had my MK4 I ran 807 tubes in it. On each side I had one Soviet and one Canadian Westinghouse. I didn’t worry about whether the tubes were microphonic or not; most tubes are anyway, if you hit them hard enough you’re going to hear something. And I don’t like the RCA‘s. Aesthetically, they lack the metal girdle that shields the wires coming down from the plate. And their sound is very bright, forward. I like the other brands much better. They are more tubey sounding, with a nice old radio intonation. National Union, Raytheon, GE, Tung Sol. I hope I haven’t left anybody out. I am using Raytheon‘s right now in my mini.
Back to top
 
 

MINI TORII & ZROCK2 both anniversaried; 'Lil Audio F-15; TECHNICS SL1200MK2 KAB MODDED TT; ONKYO 6 DISC CD; MARANTZ 2226B; SCHIIT MULTIBIT DAC; SENNHEISER HD-580s
55   IP Logged
safebelayer
Seasoned Member
****




Posts: 200
Re: Experience using 807 tube
Reply #3 - 03/13/23 at 05:34:04
 
Thanks for the suggestions. I wasn't tapping the tubes hard at all. I'll try some 5933 tubes tomorrow.
Back to top
 
 
  IP Logged
Rivieraranch
Seasoned Member
****




Posts: 2126
Re: Experience using 807 tube
Reply #4 - 03/14/23 at 01:44:43
 
I’ll bet those 5933s are JAN Sylvania. I did an A/B comparison and the 5933s had no bass.

Back to top
 
 

MINI TORII & ZROCK2 both anniversaried; 'Lil Audio F-15; TECHNICS SL1200MK2 KAB MODDED TT; ONKYO 6 DISC CD; MARANTZ 2226B; SCHIIT MULTIBIT DAC; SENNHEISER HD-580s
55   IP Logged
safebelayer
Seasoned Member
****




Posts: 200
Re: Experience using 807 tube
Reply #5 - 03/14/23 at 03:37:29
 
I'm having a different experience with the 5933wa tubes. The tone is beautiful. The bass doesn't slam, but it's definitely present. One of the most realistic sound producing tubes I've tried. Here's a list of my past tubes:

EL34: Svetlana reissues 👎, nos SED winged c 👍, NOS Mullard xf2 👍

6L6 types: nos Svetlana winged c 👍👍, tung sol reissue ok, 6p3s good, 6p3s-e 👍+, tung sol 7581a 👍

807: RCA 👍  if not microphonic, Sylvania 5933wa 👍+

Kt77: gold lion reissue 👍

Kt66: gold lion reissue ok

6ca7: NOS Raytheon ok+

If anyone has questions on a specific tube type, please pm me. Too much to write here to give reviews on each.
Back to top
 
 
  IP Logged
safebelayer
Seasoned Member
****




Posts: 200
Re: Experience using 807 tube
Reply #6 - 03/14/23 at 03:39:20
 
By the way, it appears the microphony was caused by the tubes not the adapters.
Back to top
 
 
  IP Logged
Rivieraranch
Seasoned Member
****




Posts: 2126
Re: Experience using 807 tube
Reply #7 - 03/15/23 at 00:08:06
 
I’m not surprised that those RCAs are microphonic. If they are the last gasp 1970s or 1980s production, no wonder. The RCA is have all those naked wires running from the plate down to the bottom of the tube whereas the other manufacturers put that metal girdle around the wires as they exit below the plate. I don’t know if that is more than aesthetics at work. I acquired a group of 1970s RCA 807 tubes And they tested extremely high for trans conductance, 6000 to put that in perspective the older national union and other tubes tested around 3800 to 4400. Mind you this is the 6L6 test data which calls for 5000 as a normal tube. So the high trans conductance explains the lively presentation
Back to top
 
 

MINI TORII & ZROCK2 both anniversaried; 'Lil Audio F-15; TECHNICS SL1200MK2 KAB MODDED TT; ONKYO 6 DISC CD; MARANTZ 2226B; SCHIIT MULTIBIT DAC; SENNHEISER HD-580s
55   IP Logged
Pages: 1
Send Topic Print