350B vs 6L6GC in MC30?

[Seamaster]

Generally WE350B is considered the holy grail for its type, I am very curious if moding a pair of MC30s is going to take the amps to the next level? I understand the current draw is different, much higher with 350B but I think MC30’s transformers can handle them. What do you think?

 

[c_dk]

Holy grail according to who?

Certainly not to FM, GG, SC, DOB, MN, or the plethora of other top flight engineers who actually designed the most respected tube amps from back in the day.

 

[damacman]

Holy grail according to who?

Certainly not to FM, GG, SC, DOB, MN, or the plethora of other top flight engineers who actually designed the most respected tube amps from back in the day.

Is it bad that I know who all those initials are?

 

[c_dk]

I would be more concerned if you knew all the anonymous voices on the net hustl'n tone.......

 

[CruzBay]

Got 'em all but MN. Would add Dr. LF, but he came later. Mile Nesterovic?

 

[mcgjohn]

if you want to take your MC30s to the next level, tube swaps are not going to do it, insert Jensen copper foil caps in place of the stock OEM caps; replace the 100uf cap in the feedback loop with a bipolar cap bypassed with a .47 film cap.

 

[twiiii]

It would mean modifying the amp and what would you get? Just a different color of sound. Buy a pre-amp with Graphic tone controls instead. If you need more power how about a MC 60 or MC 2000. If you don't like KT 88s there is alway a MC3500. Remember to hear a real difference in level you need 5 or 6 db increase. So a MC 2000 or two mono 275 are the choice to make. Now if you are a tube roller, I don't have an answer for you. I can't take you to a test bench With Davie Obrien as he did with me and try different pairs of tubes in my 240 and take measurements. None of the Mullards, Sylvanias, RCA's, telefunkens or GE's off a normal tube suppliers shelf could match the performance of the tubes Davie carried in travel cases. be they stamped with the Mcintosh name or not. I owned my share of Mac tube amps, 60's, 230, 240's, 275's installed and used 3500's, 75"s and 30's. For everything a tube roller thinks he gains he looses some where else. Thats why I gave up on tubes in 73. And though they sound pretty good today, or almost fantastic in the case of a C500T and C1100T, I can never ever go back to tubes.. If tubes were an issue in the 60's and early 70's what about tubes made in the 40's and 50's?

 

[c_dk]

I was looking at Roger's site to see when DOB started to do amp tests since I have a graph from a amp he did in 1962....since he started doing them at a dealer in Oct. 1962 this graph from Nov. 1962 would be maybe the second or third......anyway according to Roger's site even the Mac amps Mac specifically for Western Electric did not use 300Bs.....

 

[62caddy]

Factory used RCA 1614 OTs in the MC30 but hardly anybody uses them, opting for glowing 6L6GCs instead. NOS RCA 1614 quad sets sell for very little compared to Mc-branded 6L6GC by GE.

Mc- branded 6L6GC by RCA? Don't ask.

 

[Seamaster]

if you want to take your MC30s to the next level, tube swaps are not going to do it, insert Jensen copper foil caps in place of the stock OEM caps; replace the 100uf cap in the feedback loop with a bipolar cap bypassed with a .47 film cap.

Already done that. I have two pairs of MC30, one pair is a Yazaki/Jeff day version, which are already beyond MC30.

 

[Seamaster]

It would mean modifying the amp and what would you get? Just a different color of sound. Buy a pre-amp with Graphic tone controls instead. If you need more power how about a MC 60 or MC 2000. If you don't like KT 88s there is alway a MC3500. Remember to hear a real difference in level you need 5 or 6 db increase. So a MC 2000 or two mono 275 are the choice to make. Now if you are a tube roller, I don't have an answer for you. I can't take you to a test bench With Davie Obrien as he did with me and try different pairs of tubes in my 240 and take measurements. None of the Mullards, Sylvanias, RCA's, telefunkens or GE's off a normal tube suppliers shelf could match the performance of the tubes Davie carried in travel cases. be they stamped with the Mcintosh name or not. I owned my share of Mac tube amps, 60's, 230, 240's, 275's installed and used 3500's, 75"s and 30's. For everything a tube roller thinks he gains he looses some where else. Thats why I gave up on tubes in 73. And though they sound pretty good today, or almost fantastic in the case of a C500T and C1100T, I can never ever go back to tubes.. If tubes were an issue in the 60's and early 70's what about tubes made in the 40's and 50's?

I have tried/owned MC60, MC75, MC275, they all, nowhere near a regular pair of MC30's musicality, hence the quest for more MC30. MC60, a bass monster, and the bass dominated the rest. MC75, they are good, but too 2 dimensional sounding, and dry for tube amps, same apply to MC275.

 

[Seamaster]

I hope my replies did not hurt anyone's feeling. It is just me, I personally feel the M60, MC75, and MC275 lack the tube harmony and magic.

 

[c_dk]

Knowing a few of those initialed engineers who designed those amplifers and having a pretty good idea of what their candid, back room observations would be, I hope you won't be offended......

I do know some questions they would ask though......

What speakers do you own? Have you explored how they interact with your room accoustics?

What sound differences do you notice between your sources? Are you using a turntable as your primary source? Setup and calibration?

These questions were the foundation of all the presentations made by the McIntosh principles I ever had the chance interact with.......their electronics were designed to do a specific job. The transducers needed to be done correctly so that the electronics could then do their job correctly.

 

[mcgjohn]

Already done that. I have two pairs of MC30, one pair is a Yazaki/Jeff day version, which are already beyond MC30.

very cool.

the other option is to increase the neg bias, and try a pair of 6550s in place of the 6L6s. The added heater current draw should not be an issue.

 

[Pio1980]

very cool.

the other option is to increase the neg bias, and try a pair of 6550s in place of the 6L6s. The added heater current draw should not be an issue.

Why not 6CA7?

 

[Mike Gibson]

I hope my replies did not hurt anyone's feeling. It is just me, I personally feel the M60, MC75, and MC275 lack the tube harmony and magic.

I see no reason for anyone to be offended by your comments. As you stated they are your personal opinions and come by from experience with the amps in question. Only a fanboy would be offended and those folks seldom think logically. As for me the 275 adds a sparkle to the 902 horns in my Altecs the SS amps I have do not possess. But again that's just me and my experience. YMMV. I hope you find what you seek and please keep us informed of your journey.

Mike

 

[quartersaw]

Why not 6CA7?

Different pinout...(?)

 

[Pio1980]

Different pinout...(?)

Indeed, tie 1 and 8 on the socket.

 

[leftside]

I hope my replies did not hurt anyone's feeling. It is just me, I personally feel the M60, MC75, and MC275 lack the tube harmony and magic.

When I first plugged in my MC75's with the B&W 805S I too felt the same. As much as I loved the sound, there was something missing. It was a tiny bit dry. I tried out a few different speakers and settled on my current speakers - the Dynaudio C1's. I couldn't be happier with this combo. Amps certainly make a difference to the sound, but I've found the source and the speakers to make more of a difference.

Keep us updated. I'm interested to hear how much more you can get out of the MC30's.

 

[mcgjohn]

Why not 6CA7?

have never tried that one....may need to do a little socket work.

the 6550 is an easy swap, and is similar to sticking a V-8 in place of a 4 banger in a small car. The MC30 takes on an ease to the sound that is not available with the 6L6 varieties.