RAAL-requisite: The Official VM-1a Discussion Thread
Feb 6, 2024 at 8:16 PM Post #61 of 75
Feb 6, 2024 at 11:57 PM Post #62 of 75
Accurate. I had to rearrange my whole rack for this amp. Worth it, though.
Yup....best to stick tube electronics, especially amps, on the top of the rack and allow all that heat to dissipate up and away easily.
 
May 14, 2024 at 4:30 PM Post #64 of 75
Welp, I guess it's time to pander for tube recommendations.

Since the VM-1a is still seemingly the king-of-the-hill for ribbon headphones, including the Immanis, has anyone tried rolling the tubes? If so, with what? The successor to the VM-1a will supposedly use 300Bs, but I'll be sticking with the VM and therefore thought it best to put in the work to dial-in the sonics.

@paradoxper and @normie610. I vaguely remember you gents looking into this a while back? Do you have any recommendations?

Current Tube List:
1 x 6SN7GTB TUNG-SOL NOS
6 x Mullard EL34s
 
May 14, 2024 at 6:13 PM Post #65 of 75
Welp, I guess it's time to pander for tube recommendations.

Since the VM-1a is still seemingly the king-of-the-hill for ribbon headphones, including the Immanis, has anyone tried rolling the tubes? If so, with what? The successor to the VM-1a will supposedly use 300Bs, but I'll be sticking with the VM and therefore thought it best to put in the work to dial-in the sonics.

@paradoxper and @normie610. I vaguely remember you gents looking into this a while back? Do you have any recommendations?

Current Tube List:
1 x 6SN7GTB TUNG-SOL NOS
6 x Mullard EL34s
Unfortunately I don’t have VM-1a. If I remember correctly, you can also use 6SL7 tubes with VM-1a, but it will have more gain than 6SN7. I only have experience with 6SL7, since my preamp uses that. The best sounding of the lot in my system is Mullard ECC35 short brown base tall bottle (a little bit difficult to find nowadays), followed by Tung Sol 6SU7GTY, Brimar CV1985, and Fivre 6SL7GT, RCA 5691 red base (all of them are NOS). One caveat, the sound of these tubes will depend on the output/power tubes, so you have to do some mix and match.

I don’t have any experience with EL34.
 
May 14, 2024 at 6:20 PM Post #66 of 75
Unfortunately I don’t have VM-1a. If I remember correctly, you can also use 6SL7 tubes with VM-1a, but it will have more gain than 6SN7. I only have experience with 6SL7, since my preamp uses that. The best sounding of the lot in my system is Mullard ECC35 short brown base tall bottle (a little bit difficult to find nowadays), followed by Tung Sol 6SU7GTY, Brimar CV1985, and Fivre 6SL7GT, RCA 5691 red base (all of them are NOS). One caveat, the sound of these tubes will depend on the output/power tubes, so you have to do some mix and match.

I don’t have any experience with EL34.

Awesome info - thanks, Normie!

I'm looking hard at the Kenrad 6SN7GT/VT-231, but shopping for NOS tubes can be a shockingly convoluted and fraud-riddled crapshoot. I might take a flyer on one, but it seems smarter to stick with tubes made by current manufacturers.
 
Last edited:
May 14, 2024 at 6:38 PM Post #67 of 75
Awesome info - thanks, Normie!

I'm looking hard at the Kenrad 6SN7GT/VT-231, but shopping for NOS tubes can be a shockingly convoluted and fraud-riddled crapshoot. I might take a flyer on one, but it seems smarter to stick with tubes made by current manufacturers.

get in touch with Dale at vacuumtubes. he should have some KR VT231.

yes, you can use 6SL7 tubes. I've used mullard ecc35 with nice results. mid/upper mid centric sound. much more gain than 6sn7 tubes thus less turn on the volume knob too.

I'm using KR VT231 and EL34 mullards on mine. have tried the new apos special reserve 6sn7 but didn't like it too much..

NOS TS 6sn7gtb is a safe bet and good all rounder.
 
May 14, 2024 at 6:47 PM Post #68 of 75
get in touch with Dale at vacuumtubes. he should have some KR VT231.

yes, you can use 6SL7 tubes. I've used mullard ecc35 with nice results. mid/upper mid centric sound. much more gain than 6sn7 tubes thus less turn on the volume knob too.

I'm using KR VT231 and EL34 mullards on mine. have tried the new apos special reserve 6sn7 but didn't like it too much..

NOS TS 6sn7gtb is a safe bet and good all rounder.

I really like musicality, visceral impact/tactility and 3D holographic staging, so either the KR VT231 or the Melz 6N8S seem like the best fit.

I'll reach out to Dale just as you recommended. Thanks, Roasty!
 
May 14, 2024 at 6:54 PM Post #69 of 75
Welp, I guess it's time to pander for tube recommendations.

Since the VM-1a is still seemingly the king-of-the-hill for ribbon headphones, including the Immanis, has anyone tried rolling the tubes? If so, with what? The successor to the VM-1a will supposedly use 300Bs, but I'll be sticking with the VM and therefore thought it best to put in the work to dial-in the sonics.

@paradoxper and @normie610. I vaguely remember you gents looking into this a while back? Do you have any recommendations?

Current Tube List:
1 x 6SN7GTB TUNG-SOL NOS
6 x Mullard EL34s
You'll be limited with 6LS7 selection and want to roll through the Mullard XF EL34 range as they're by far the best.
 
May 15, 2024 at 5:36 PM Post #71 of 75
You'll be limited with 6LS7 selection and want to roll through the Mullard XF EL34 range as they're by far the best.
I picked up 12 x new (old stock/unused) Mullard XF2 double halo EL34s. My wallet almost packed up it's credit cards and left. Ouchies...

get in touch with Dale at vacuumtubes. he should have some KR VT231.

yes, you can use 6SL7 tubes. I've used mullard ecc35 with nice results. mid/upper mid centric sound. much more gain than 6sn7 tubes thus less turn on the volume knob too.

I'm using KR VT231 and EL34 mullards on mine. have tried the new apos special reserve 6sn7 but didn't like it too much..

NOS TS 6sn7gtb is a safe bet and good all rounder.
Amazing recommendation on Dale...thanks again, Roasty. I emptied his stock of the EL34s above. It is shocking how expensive these old tubes are getting. I'm going to pit the KR VT231 against the Melz 1578 and see what I like most. Seems like the KR VT231 kicks like a mule?
 
May 15, 2024 at 7:18 PM Post #72 of 75
@Hiker816 i tried the melz a while back. KR is still tops for me. try and source a nice mullard ECC35 for a different flavour. it sounds great with the vm1a on triode mode.

on a diff note, last night I tried Zähl HM1 as pre into the vm1a and the tone controls work great to dial down a bit of top end and bump up the low end, tastefully.
 
May 15, 2024 at 7:51 PM Post #73 of 75
on a diff note, last night I tried Zähl HM1 as pre into the vm1a and the tone controls work great to dial down a bit of top end and bump up the low end, tastefully.
Coincidentally, I tried the same yesterday! And I agree--the tone controls (and soundstage knob) worked to great effect. Some of my motivation, though, was to test whether the interface was playing a role in the Zahl issue I've been having with the Immanis (detailed in the Immanis-Magna thread), since there's no need for the interface when using the Zahl as a pre to the VM1a. I was getting a little of the dissonant distortion/boom with distortion-heavy metal tracks between the mid-bass and lower mids that I got with the Zahl through the interface, but it was certainly less. And it's a really circumscribed problem to begin with--for 90% of the music I listen to (and I bet a higher percentage for most others) the Zahl through the interface is perfect. It's just that the VM1a is always perfect. :L3000:
 
May 15, 2024 at 9:36 PM Post #74 of 75
I picked up 12 x new (old stock/unused) Mullard XF2 double halo EL34s. My wallet almost packed up it's credit cards and left. Ouchies...


Amazing recommendation on Dale...thanks again, Roasty. I emptied his stock of the EL34s above. It is shocking how expensive these old tubes are getting. I'm going to pit the KR VT231 against the Melz 1578 and see what I like most. Seems like the KR VT231 kicks like a mule?
Yes, that all too familiar feeling. It's only temporary.
 
May 15, 2024 at 9:58 PM Post #75 of 75
@Hiker816 i tried the melz a while back. KR is still tops for me. try and source a nice mullard ECC35 for a different flavour. it sounds great with the vm1a on triode mode.

on a diff note, last night I tried Zähl HM1 as pre into the vm1a and the tone controls work great to dial down a bit of top end and bump up the low end, tastefully.
expensive way to tinker with what to me is the best option for RAAL HP's
 

Users who are viewing this thread

Back
Top