TW Rocket

[Blues Hound]

Martin,

Sorry of the typo, Pin 6 is 258.5 VDC.

I will check the cathode resistor, to make sure it is 1.5k.

Thanks,
Steve

[Bob S]

I like that B+ voltage. 300 to 310v is a good place imho.
A little gentler on the output tubes.
6p14p is the basic Soviet version of an el84. The ev suffix is a select version (longer life or some such). There's a k suffix for something else - might be hardened/less prone to vibration. One of our experts might chime in.
They're all good anyway & you can beat them like a 7189.
Dr Z might well have bought the majority of them.
Oh & good catch Martin.
Nice build!

[rp]

6p14p is the basic Soviet version of an el84. The ev suffix is a select version (longer life or some such). There's a k suffix for something else

This is from one of the good people here that i saved:

The Sovtek EL84M *is* a rebranded 6П14П-EB = 6P14P-EV - same Reflektor factory, same tooling, same templates, same construction, same materials, same everything. Ditto for their EL84 = 6П14П = 6P14P.

Some NS-sourced batches can be quite poor because of sloppy production and lack of real QC. Vintage OTK models - I would say pre-1983 or so - are much better in that respect, they can still be found from Eastern European (r)etailers.

Russian suffixes:

P (Cyrillic) = R (Roman) = special quality
E = E = extended lifetime
B = V = ruggedized
K = K = vibration resistant

Russian equivalents of the EL84:

6П14П; bog standard version, large thick glass = EL84, 6BQ5
6П14П-EB; hardened version, longer lifetime = EL84M, 7189
6П14П-EP; special quality, longer lifetime = E84L, 7320 (quite rare)
6П14П-K; hardened version, vibration resistant = EL84F (very rare)

[Blues Hound]

Martin,

Apparently I am s bit dyslectic or color blind, as it was a 1.2M.

Swapped it out for a 1.5K, all voltages are looking very good and the amp sounds very good.

Pin 1 V1, Pin 2 V2 115.2 VDC, Pin 3 V2 115.1 VDC

I am in your debt sir...

Steve

[martin manning]

Not at all, Steve. The complete set of voltages and good pictures made it easy.

[Blues Hound]

Bob and RP,

Thanks for the information, I currently have JJ's in and they sounds very good, is there a big difference between the JJ's and the Sovtek's?

Steve

[Blues Hound]

I have seen that others have built 2x EL84 Rockets, would it be possible to put in a half power switch ala Dumble and run it with just two of the EL84's?

Thanks,
Steve

[martin manning]

You would need to double the cathode resistor value and double the speaker load (mismatch the impedance selector down one click).

[Bob S]

If the 6p14p's are 70s they are as good as any nos el84s - European or US made, to my ears anyway.
It might be that I'm unlucky, but I've never had much luck with JJs.
Some are good, but some aren't.

[norburybrook]

I bought some Russian valves for my rocket/Z-wreck from a guy in Russia via Ebay. They're great, I had one red plating JJ so thought I'd give the Russian valves a try. The rocket/wreck runs the output valves very hard.



M

[Blues Hound]

Tried some Ruby 7025/12AX7's in the Rocket...way more treble...put the Mullard's back is as I think they sound better...going to try the Ruby's in the Express clone...

Have a quad of the Russian 6p14p-cv's on the way, will report back after I get them.

This amp is becoming a favorite...

[Blues Hound]

Quick update:

Had the quad of the Russian 6p14p-cv's in the amp for a while and ended up putting the JJ's back in...they just sound better.

Steve

[M Fowler]

I find that JJ's are much better tubes myself.