PrimaLuna Prologue 5 and tube upgrades


Coming from the pro audio world and sitting most of my career in front of extremely flat loudspeakers in acoustically treated rooms, I'm a bit concerned that my brand new Prima Luna Prologue 5 tube amp is quite rolled off from 10k on upward.
I'm sure most would call this "warm" and the typical tube sound, but I would just call this in need of a pink noise generator and a eq adjustment. I am in love with the 3D dimensionality and the incredible soundstage from this amp, but am left craving the pings of cymbals and the air of vocals on playback.
So far, I've only just replaced the 12ax7's with some 70's phillips that I had around. It helped just a small bit with the extention of the highs. Should I chase this down with some great Telefunkens etc? or go back to a solid state amp? Yes, I'm calling Kevin from Upscale later today!
jmacinnis
The below combination works well for me/my stereo

PL3 Tubes = 12AX7 Telefunken Black Smooth Plates, 12AU7 = Radiotechnique, 5R4GYS = Philips

PL5 Tubes = KT88 Gold Lion (May try Psvane), 12AX7 = Bugleboy, 12AU7 = Radiotechnique

PL8 Tubes = 12AX7 Telefunken Black Smooth Plates, 12AU7 = Radiotechnique, 5R4GYS = Philips

I use Crystal Cable solid silver 999.999 Speaker Wire, RS Audio and MAC Paladium IC's.

REL 305 Sub, Triangle 30th Anniversary Antal Speakers, Townsend Super Tweaters.

I have not gone down this path myself, but from what I am reading, upgraded fuses add to the realism.

I have used Mullards, Tungsgram, and a couple others.What I have outlined above is what works best so farand results in a very realalistic upper end regardless of instruument. I have read good reviews regarding the new production Psvane Treasures, both 12AX7, and 12AU7

You may want to mention what speakers you are driving, some fellow Audio Goners may have xperience with the combo.

Brad

Hope This Helps.




I also come from the land of Pro Audio and felt the same way about my Jolida 502p until it broke in a bit and I messed around with various tube options. Now I wonder what the hell I was thinking as it has sparkle galore. Also, this might be the first time I've used the word "galore."
Another option is Andy Bowman at Vintage Tube Services. Tell him what you're trying to accomplish and he'll give you some good advice (and excellent NOS tubes).
http://vintagetubeservices.com/
"left craving the pings of cymbals and the air of vocals on playback"

what you are describing is sluggish, compressed high frequency transients...try some NOS Ei or NOS Telefunken 12AX7s. I have a pair of worn out JAN Phillips 12AX7WA's that sound exactly as you described and the highs do seem to be where I first hear pre tubes aging.
FWIW I agree with David re EI 12AX7A's. These tube have a bit more gain than others, excellent clarity and extended highs. If you buy NOS make sure they are tested, and buy an extra in case you have a failure.

I don't know what small tubes Primaluna is currently using. Last I knew it was EH's - not the best IMHO. But if this amp is new do give it a couple of hundred hours to break in before you start switching everything around.
Thanks gents.

Wescoman...your advice to speak with Andy at Vintage Tube Services was priceless and Brad, He pointed me to the Bugleboys like you have in your PL5. Also, very curious about your "supertweeters"?
Their website was truly interesting.
Replacing 12AX7s with "preferred" 7025s from the tubestore added some sparkle to my amp at an amazingly low cost. Same with some JAN Philps 12AT7s. I like it when a company recommends LESS expensive options that may lack the collector buzz (and prices) but still sound great.
I ended up with Bugle Boy's NOS from mid 1960's from Vintage Tube services. It really did add a bit of 12k upwards back to my setup. Also, the imaging and soundstage seems a bit more interesting and enveloping now too.
After one of my JAN Philips 12at7s decided to commit Hari Kari it was suggested by Thetubestore I try the Mullards, and they're on the way.
so i broke out the audiotools and a DPA microphone through my apogee/mac interface. I pushed pink noise through the RTA and found that there is nearly nothing getting through over 18k. Tonight, I'm going to bring out my old yamaha amp and see if it the Prima Luna/Van Alstine combo or the speakers doing this to the signal. ugh.
Nothing getting through above 18K and you think that matters? You must be very young. Or of the canine persuasion. :-)
If you want to wake up the top end extension, definition and dynamics of your Prima Luna, without losing the aspects you enjoy:

1/ NOS Siemens or Siemens-Halske 12ax7. If you need a less expensive alternative, NOS Valvo. Among current production 12ax7, the Northern Electric 12ax7 and their Preferred Series 7025 sound particularly open.

2/ The bigger difference will be made by changing the power tube. Among current production KT88s, the cryogenically-treated Valve Art that tubeman.com sells is the burstiest, most wide-open KT88 I can think of, short of finding a quad of unobtainium KR KT88s from around 2000-2002 (I know where some are). For this Valve Art KT88, cryo makes all the difference in exactly what you're looking for. These tubes will have some glare and brigthness to them for the first week or so, and then settle in to a nice, linear character. Bass is also audibly improved over the Russian production KT88s, or the darker sounding EAT and Shuguang Black Treasure.

Phil
So this is common eq'ing with tubes? I'm not sure I'm patient enough or rich enough?!
most of the new manufactured pre tubes are awful for good tube equipment... I've yet to find any I like after prolonged listening although the Prima Luna tubes are a safe bet for a tube thats musical but not detailed. And the NOS tubes definitely have sonic characteristics. Mullards, Siemens, Amperex, and Telefunkens from early 70's and before seem to work well, after that tube manufacturing went down hill with the exception of some Eastern Europe tubes in the early 80's. And it does cost, hard to find good NOS tubes for less than $50 per tube with 12AX7's the dearest.

BTW I heartily recommend the KT-120's instead of KT-88's...they remedy the main ill's that the reviewers have critiqued Prima Luna Prologue for, dynamic compression and missing low bass. They will however shine a spotlight on any distortion from your pre tubes, I found this especially noticeable on complex choral passages and ended up completely reshuffling my pre tube complement to eliminate.
I've been reading about non-feedback topology amplification and it being prone to be frequency limitations if not matched with the absolute perfect speaker system. Truth to this? If so, where are these perfect speakers that will give me the sparkle back?
Good thread, and extremely helpful to me as I purchased a PrimaLuna Prologue 5 just last week! Great advice with recommended tubes! Thank you. Once I start getting into some good tubes I'll report back!
Jmacinnis - I was doing some research on the Prologue 5 and found your post. Did you ever get this sorted out?

Do you still have the amp?