[UntilThen]

I haven't use the 5998 switch much. On the last occasion, I was specifically trying to hear any difference when I flick the switch. Could be my ears playing tricks but I thought it sounded just a mite louder when I had the boost switch on. Apart from that, I could detect no difference.

I don't use it much because I'm under the illusion that it will burn up my 5998 faster.

 

[UntilThen]

What will make a bigger difference is using four 5998 instead of two but that will be depleting a scare resource faster.... and that is a big no no. We must use 5998 frugally.

 

[lukeap69]

What will make a bigger difference is using four 5998 instead of two but that will be depleting a scare resource faster.... and that is a big no no. We must use 5998 frugally.

Ha! I am ready for this comment. I have 4 on the way so I can try that. I don't worry much about the scarcity, other tubes sound very good as well so let's use four 5998's to our hearts' content.

 

[yates7592]

Can users please tell me what types of 6BL7 tube are better than others?

 

[2359glenn]

@UntilThen Matt

Does the 5998 switch make much difference? I have TS5998 on the way but would like to know if I will be missing much because my Darna does not have the 5998 switch.

The 5998 will still sound good it just sounds better with the switch on

 

[yates7592]

And another one - 5V rectifiers - advice please as to best ones to start out with beyond HEXFRED plug-in.

 

[rnros]

Can users please tell me what types of 6BL7 tube are better than others?

Did you mean 6BL7s or 6BX7s? Both good, I think most prefer the BX7s. On the BX7s, I have/use Sylvania, GE, and RCA. I typically use 4 Sylvania and 2 GE or RCA.
With my BX7s, I actually selected tubes/pairs for lack of noise, so that's why the mix of brands. I may purchase more, they are very good
Don't remember which BL7s I have, haven't used them for a while.

And another one - 5V rectifiers - advice please as to best ones to start out with beyond HEXFRED plug-in.

Some that I have tried:
Good and low cost ($5 TO $20): 5CU4, 5AW4, and 5C3S (Soviet/Svetlana). I went with Glenn's recommendations, I think he recommended all of these.
At higher cost, and very good, Mullard GZ37, available at Langrex, about $110. Also recommended by Glenn.
Adapter req'd: GE 1641/RK60, Very good/excellent tube at reasonable cost, about $40.
(The only adapter I found for this tube is prone to very slight vibration, solve that problem and the 1641 competes with the UE596.)
Adapter req'd: UE 596, Excellent tube, higher cost, and (very) difficult to find, about $150.
I rotate all of these from time to time, 5CU4 probably my favorite in the low cost category. The 1641/RK60 usually stays in the amp unless I'm rolling another tube.
These are all good, so depends on your ear, power tubes and headphones.

There are many others, I'm sure others will provide options, and you can search the thread also.

 

[mordy]

Can users please tell me what types of 6BL7 tube are better than others?

Hi yates7592,

Some time back I compared different 6BL7 tubes and I seem to remember that I liked the late 50's early 60's X- plate tubes tubes from Tung Sol and GE (GE may have made some of the TS tubes).
However, this was in a different amp and only as pairs.
I am not sure how critical the brand selection is when you use six of them together.
I have 6BL7 tubes from Sylvania, RCA, GE, Tung Sol, Westinghouse and Raytheon.
A quick check of eBay reveals over 400 offers. It seems that it is still possible to snag a sextet for $3-5 each with some careful shopping.

 

[UntilThen]

Ha! I am ready for this comment. I have 4 on the way so I can try that. I don't worry much about the scarcity, other tubes sound very good as well so let's use four 5998's to our hearts' content.

You bought 4? Salute !!!

 

[whirlwind]

Since the 5998 switch is on the amp...I always have it on, just so I don't feel I am missing anything.

It is not necessary , the 5998 tube will still sound good, it is just that it can be pushed harder, and Glenn has allowed that.

I use it for 6336 A/B tubes also.

Listening to some Robert Plant with this combo now.

 

[2359glenn]

Those that are afraid to use the 5998 switch. When using the 5998 in the OTL the current through it will be lower.
When the switch is on it brings the current back up to normal. This is not cooking the tubes they are running properly with the switch on.
Don't use it with normal 6AS7s 6BL7s 6BX7s or other 6AS7 types.
Fine to use ir with 6336 it will bring the impedance down

 

[UntilThen]

Alright switch on for 5998 it will be from this point forward. I will do it tonight.

 

[gibosi]

And another one - 5V rectifiers - advice please as to best ones to start out with beyond HEXFRED plug-in.

With respect to 5V rectifiers, this is a good place to start:

https://www.head-fi.org/threads/dub...mparison-rectifer-tube-rolling-thread.694525/

 

[leftside]

Some good rectifiers here. These are quite rare with the twin getters:
https://www.ebay.ca/itm/CV717-5R4G-...ew-Old-Stock-ValveTube-1-pc-A17D/391765269145

 

[gibosi]

Some good rectifiers here. These are quite rare with the twin getters:
https://www.ebay.ca/itm/CV717-5R4G-...ew-Old-Stock-ValveTube-1-pc-A17D/391765269145

Although labeled Haltron, I believe these were manufactured by Brimar. And I would agree, IMHO, this is a very good rectifier.