xoundmind

Many thanks for all of the responses.

Jeff: Is it actually lowering the resistance too...which would have the combined effect of lowering the voltage. I’m possibly not following what you’re saying. thanks

In the hope of learning more about tube HiFi, what is the rationale for having two rectifier tubes in a circuit? Is this more prevalent in SET amps? (I know that some - particularly Mesa Boogie - guitar amps have two rectifiers, but it is not at all common.) Thanks for any wisdom on the matter.

Well, I replaced the JJs in my phono stage with those 7025s and I actually like the tone a bit better. Having said, that did not get eliminate any of the hiss. After trying every imaginable combination of tube vs solid state for phono stage, preamp and power amp, it’s pretty clear that the culprit is phono with my PrimaLuna Prologue Four. I swapped in some newer 12ax7s in that and that didn’t help at all. Maybe the transformers in the amp don’t like phono?

Did you ever end up getting this?

I thinking about these; $15 from tube depot (and I just need three). https://www.evatco.com.au/the-new-eh-7025/ have you tried them?

Many thanks for the advice.

That’s an open question. 😀 my cursory reading on the matter indicated the other two are good choices.

Hi i have some unwanted hiss in my system, which I have isolated to the phono stage. I have some 9 month (age of the phono stage) old JJ 12AX7s in there now, but I don’t think it’s indicative of a problem with any of them. If I were to swap in some 5751s or 7025s, which would likely be better for a phono stage? Thanks

I’m using the 4 ohm tap on my PL power amp with wharfedale Denton 80 speakers. It’s magic.

I’ve live with a PL Prologue Four power amp for about 6 weeks and it’s fantastic. It’s my first tube power amp, so no real point of reference, but wow.

Listening to a mono pressing of this right now.

by NULL caps, do you mean RCA caps?

Any onclusions to draw from this thread? 😉 I have some Wharfedale Denton 80s. Great speakers, btw! They have two sets of binding posts, but I’m baffled as to how bi-wiring could make a difference. if someone can sell me on the idea, please do. 😀

What’s the efficacy of a ground loop isolator in this type of situation

On the subject of single ended amps, any recommendations on a kit? A common one seems to be Douk, but have some reservations after reading various threads around the web. thanks

Any discernible tone difference?

Since this thread was unearthed... I saw folks mentioning using a 5751 for 12AX7. Is that really a good idea and what’s the expected result?

What’s your max budget number?

Integrated or power amp?

I was thinking about getting one for fun, but just noticed that they are out of stock; presumably made in China...

Another option to get your feet wet is the Tube Cube: https://www.tubedepot.com/products/tubecube-7-stereo-vacuum-tube-amplifier It’s only 3.5 wpc, by you might find yourself getting the tube bug and wanting to make a major upgrade. I question whether any of those amps you listed have any resale value.

I’m assuming there aren’t any “stereo doctors” near you. How about a well tech, who repairs tube guitar amps?

Anyway...others with an opinion on the Decware amps? Maybe I’ll try the forum search. 🤔

“Triode amps such as the Model 8, using global negative feedback are also boring to hear, continuously playing music back, out-of-time. Are we building SE amps, or, are they SE tuners ?? E.E.s are trained in their classrooms, to add negative feedback loops to SE all-triode amps. Discriminating music-lovers will RIP THEM OUT !!” Jeffrey, given the above, what is your take on Decware amps?