Amp/Tube/Speaker Matching Advice (Primaluna Prologue w/ Mythos ST-L)

[Finkdigital]

Hello Gentleman. Now that I've trolled around for years and stolen all of the fantastic information that you selflessly post, I promise to start contributing more now that I have learned enough where I actually have something to contribute. Today, I'm hoping to get some tube advice from the community- specifically, which tubes for a desired sound...

I'm currently running a Concept 16.5 receiver (with recent full restoration by Pacific Stereo) as an amplifier only with a Modwright 9.0SE as the pre. The amp is vintage but has a somewhat modern hi-fi sound (Richard Schram design). The pre amp is very neutral while the Concept amp is also fairly balanced with maybe a slightly rolled off top end. The amp is way too powerful for my (moderately) sensitive Mythos ST-L speakers. So as much as I love the Concept 16.5, it's up for sale.

I just purchased a set of a set of Primaluna Prologue 5 monoblocks with old KT88s so I can't judge the sound of the monoblocks yet bc the tubes are done. I need to replace the (8) power tubes in the amps and I'm trying to decide which tubes will get me the sound I'm looking for. I listen to absolutely everything from Hip-Hop to Classical.

The (Definitive Technologies) Mythos ST-L is as versatile a speaker as I could possibly afford (and I love the **** out of them). They are self powered so bass is powerful and extended as long as it's present in the signal (digital crossover in the speaker gets the low pass from the speaker-level in). The speakers are generally neutral but I feel like they slightly lack low-mid and mid range (male vox) and could use a bit more high end sizzle as well. In terms of sound stage, I think they image well in terms of depth but could use a little help in terms of width. I was thinking EL34 but these amps accept a wide variety- KT88, 6550, KT90, EL-34, KT77, 6CA7, 6L6GC, KT66, 7581, EL37. I'm willing to spend more than the cheapest (maybe $20-40 per tube?), but not for high end NOS. What do you guys think? Sorry for the long post (I tried my best to edit. Thanks in advance

 

[cade12]

Try a set of Tubg-Sol KT120. I had a quad of them in my Prologue 2. That's where I stopped rolling power tubes.

You didn't really ask, but try some Radiotechnique 12au7 and Tungsram 12ax7 in those puppies as well. Sweet mother of all that is holy!

 

[cade12]

Also, your signal and driver tubes will do far more to alter the sound than the power tubes.

 

[Finkdigital]

Thanks, that's interesting. I'll try signal and driver tubes first then. I have the stock Primalunas- not sure what the OEM is. Where would you go if you wanted to get more midbass out of the amp?

Why does it seem like every discussion of amp tube rolling focuses on the effect of the big output tubes if the smaller signal and driver tubes are more effective and cheaper to roll?

 

[for_p1]

Hello Gentleman. Now tve trolled around for years and stolen all of the fantastic information that you selflessly post, I promise to start contributing more now that I have learned enough where I actually have something to contribute. Today, I'm hoping to get some tube advice from the community- specifically, which tubes for a desired sound...

I'm currently running a Concept 16.5 receiver (with recent full restoration by Pacific Stereo) as an amplifier only with a Modwright 9.0SE as the pre. The amp is vintage but has a somewhat modern hi-fi sound (Richard Schram design). The pre amp is very neutral while the Concept amp is also fairly balanced wis way too powerful for my (moderately) sensitive Mythos ST-L speakers. So as much as I love the Concept 1

Hello Gentleman. Now that I've trolled around for years and stolen all of the fantastic information that you selflessly post, I promise to start contributing more now that I have learned enough where I actually have something to contribute. Today, I'm hoping to get some tube advice from the community- specifically, which tubes for a desired sound...

I'm currently running a Concept 16.5 receiver (with recent full restoration by Pacific Stereo) as an amplifier only with a Modwright 9.0SE as the pre. The amp is vintage but has a somewhat modern hi-fi sound (Richard Schram design). The pre amp is very neutral while the Concept amp is also fairly balanced with maybe a slightly rolled off top end. The amp is way too powerful for my (moderately) sensitive Mythos ST-L speakers. So as much as I love the Concept 16.5, it's up for sale.

I just purchased a set of a set of Primaluna Prologue 5 monoblocks with old KT88s so I can't judge the sound of the monoblocks yet bc the tubes are done. I need to replace the (8) power tubes in the amps and I'm trying to decide which tubes will get me the sound I'm looking for. I listen to absolutely everything from Hip-Hop to Classical.

The (Definitive Technologies) Mythos ST-L is as versatile a speaker as I could possibly afford (and I love the **** out of them). They are self powered so bass is powerful and extended as long as it's present in the signal (digital crossover in the speaker gets the low pass from the speaker-level in). The speakers are generally neutral but I feel like they slightly lack low-mid and mid range (male vox) and could use a bit more high end sizzle as well. In terms of sound stage, I think they image well in terms of depth but could use a little help in terms of width. I was thinking EL34 but these amps accept a wide variety- KT88, 6550, KT90, EL-34, KT77, 6CA7, 6L6GC, KT66, 7581, EL37. I'm willing to spend more than the cheapest (maybe $20-40 per tube?), but not for high end NOS. What do you guys think? Sorry for the long post (I tried my best t
t's up for sale.

I just purchased a set of a set of Primaluna Prologue 5 monoblocks with old KT88s so I can't judge the sound of the monoblocks yet bc the tubes are done. I need to replace the (8) power tubes in the amps and I'm trying to decide which tubes will get me the sound I'm looking for. I listen to absolutely everything from Hip-Hop to Classical.

The (Definitive Technologies) Mythos ST-L is as versatile a speaker as I could possibly afford (and I love the **** out of them). They are self powered so bass is powerful and extended as long as it's present in the signal (digital crossover in the speaker gets the low pass from the speaker-level in). The speakers are generally neutral but I feel like they slightly lack low-mid and mid range (male vox) and could use a bit more high end sizzle as well. In terms of sound stage, I think they image well in terms of depth but could use a little help in terms of width. I was thinking EL34 but these amps accept a wide variety- KT88, 6550, KT90, EL-34, KT77, 6CA7, 6L6GC, KT66, 7581, EL37. I'm willing to spend more than the cheapest (maybe $20-40 per tube?), but not for high end NOS. What do you guys think? Sorry for the long post (I tried my best to edit. Thanks in advance

You xan start with

Thanks, that's interesting. I'll try signal and driver tubes first then. I have the stock Primalunas- not sure what the OEM is. Where would you go if you wanted to get more midbass out of the amp?

Why does it seem like every discussion of amp tube rolling focuses on the effect of the big output tubes if the smaller signal and driver tubes are more effective and cheaper to roll?

You can start wich cheap things - get

Hello Gentleman. Now that I've trolled around for years and stolen all of the fantastic information that you selflessly post, I promise to start contributing more now that I have learned enough where I actually have something to contribute. Today, I'm hoping to get some tube advice from the community- specifically, which tubes for a desired sound...

I'm currently running a Concept 16.5 receiver (with recent full restoration by Pacific Stereo) as an amplifier only with a Modwright 9.0SE as the pre. The amp is vintage but has a somewhat modern hi-fi sound (Richard Schram design). The pre amp is very neutral while the Concept amp is also fairly balanced with maybe a slightly rolled off top end. The amp is way too powerful for my (moderately) sensitive Mythos ST-L speakers. So as much as I love the Concept 16.5, it's up for sale.

I just purchased a set of a set of Primaluna Prologue 5 monoblocks with old KT88s so I can't judge the sound of the monoblocks yet bc the tubes are done. I need to replace the (8) power tubes in the amps and I'm trying to decide which tubes will get me the sound I'm looking for. I listen to absolutely everything from Hip-Hop to Classical.

The (Definitive Technologies) Mythos ST-L is as versatile a speaker as I could possibly afford (and I love the **** out of them). They are self powered so bass is powerful and extended as long as it's present in the signal (digital crossover in the speaker gets the low pass from the speaker-level in). The speakers are generally neutral but I feel like they slightly lack low-mid and mid range (male vox) and could use a bit more high end sizzle as well. In terms of sound stage, I think they image well in terms of depth but could use a little help in terms of width. I was thinking EL34 but these amps accept a wide variety- KT88, 6550, KT90, EL-34, KT77, 6CA7, 6L6GC, KT66, 7581, EL37. I'm willing to spend more than the cheapest (maybe $20-40 per tube?), but not for high end NOS. What do you guys think? Sorry for the long post (I tried my best to edit. Thanks in advance

You can start with cheap option - get Chinese kt88-98 set. But if you amp allows it - set idle current much higher than recommended. Something like 80 mA. You may like the sound.

 

[cade12]

Thanks, that's interesting. I'll try signal and driver tubes first then. I have the stock Primalunas- not sure what the OEM is. Where would you go if you wanted to get more midbass out of the amp?

Why does it seem like every discussion of amp tube rolling focuses on the effect of the big output tubes if the smaller signal and driver tubes are more effective and cheaper to roll?

More mid bass sounds like Mullards. You could try starting with KT120 for the power tubes. The increase in wattage and their increased depth over most other applicable tubes might give you exactly what you're looking for. $200 for a quad, but some of those 12ax/au7 can get pricey quickly as well.