[bcowen]

Looking at some really cheap black metal Tung Sol 6C5's whats the story on those?

Hmmm...don't know. Appears to be an earlier version of the 6J5. There are metal can versions of the 6J5 too, but I've never tried any of them. I think you need to guinea-pig the 6C5's for us.

http://www.r-type.org/exhib/aaa0060.htm

 

[JKDJedi]

Hmmm...don't know. Appears to be an earlier version of the 6J5. There are metal can versions of the 6J5 too, but I've never tried any of them. I think you need to guinea-pig the 6C5's for us.

http://www.r-type.org/exhib/aaa0060.htm

I was thinking more of this type
https://www.ebay.com/itm/283348059589

How did I get sucked down this rabbit hole of 6C5 tubes!! Thanks @bcowen
There's pricey GEC, Mullards out there and I'm reading that Pinnacle 6J5GT are the cats meow. Found some NOS JAN Sylvanias out there but they're not matching tubes (one taller than the other...but very low priced..tempting.

 

[bcowen]

I was thinking more of this type
https://www.ebay.com/itm/283348059589

How did I get sucked down this rabbit hole of 6C5 tubes!! Thanks @bcowen
There's pricey GEC, Mullards out there and I'm reading that Pinnacle 6J5GT are the cats meow. Found some NOS JAN Sylvanias out there but they're not matching tubes (one taller than the other...but very low priced..tempting.

LOL!

Haven't ever heard of the Pinnacle. There's these...if they turn out to be awesome you'd have plenty to share with your friends. Maybe me too.

 

[JKDJedi]

RCA (Cunningham) 1949 6AS7G & Tung Sol (IBM) 5998 Comparison

Preamp Tube ---> Tung Sol (Zenith) Mouse Ears 6SN7GT

Headphone used--> Beyerdynamic DT770 250OHM ( Leather Pads)


Tracks used for comparison -->

Before Your Very Eyes... (Atoms For Peace)
Streets Of Philadelphia (Bruce Springsteen)
Mi Historia entre tus dedos (Gianluca Grignani)
Creep (Radiohead)
Man Of War (Radiohead)
Has Ended (Thom Yorke)
Skinny Love (Bon Iver)



So early comparisons are that the 5998 does indeed have the higher reported amplification. To volume match both tubes I had to raise the volume on the RCA or lower it on the Tung Sol. If you own low impedance headphones the 5998 should help push them bass levels up.

The tonal signature is really hard to differentiate between the two, cudos to RCA ( with the Beyerdynamic, Sennheiser comparisons for a later date) . The Tung Sol however has the upper hand on some spots here, the cliche "full bodied" sound is here. Instruments and vocals are easily picked out, yet the RCA gels so melodiously . I like em both. The surprise here for me is the RCA, I wasn't expecting to enjoy it as much as I am now. I sent the seller a message with a huge THANK YOU!!

On some tracks it appears the RCA spreads/blends the midrange (and/or vocals) across the left to right channels. With the 5998 the vocals are more centered, more refined, almost 3d like. I can see how the RCA tubes(or 6as7g tubes in general) get this super wide description, everything gets spread out across the spectrum. The 5998 has the tighter vocal control. It's not as holographic as the RCA. Both tubes extremely enjoyable.

I use to own the later version of this RCA tube, (Mid 60's?) and do not remember them being as enjoyable as this one i have now. To stand toe to toe with the 5998 I have here is very impressive.

 

[doomjazz]

Just scored an untested IBM 5998 for ~$50 on eBay, anyone here get the other one?

After the arcing, the amp has been acting fine. I need to take the time to give a more thorough reply to everything on here, though I'll save some time and let y'all know I can't comment on Chinese dirtbikes haha. If there was a meetup that involved hifi audio and motorsports, I couldn't be there fast enough.

 

[JKDJedi]

Just scored an untested IBM 5998 for ~$50 on eBay, anyone here get the other one?

After the arcing, the amp has been acting fine. I need to take the time to give a more thorough reply to everything on here, though I'll save some time and let y'all know I can't comment on Chinese dirtbikes haha. If there was a meetup that involved hifi audio and motorsports, I couldn't be there fast enough.

I have the same one...(same price) They didn't want to sell me the one you have...lol, I tried, sent them multiple messages and no answer... Was It Something I Said!?

 

[doomjazz]

I have the same one...(same price) They didn't want to sell me the one you have...lol, I tried, sent them multiple messages and no answer... Was It Something I Said!?

The listing I won was auction style. If you were reaching out to the same seller, chances are they wanted to let the auction run its course. In this case, OBO is a competition, not a chance to get it for less than the listing price based on the seller's mood haha.

 

[bcowen]

I have the same one...(same price) They didn't want to sell me the one you have...lol, I tried, sent them multiple messages and no answer... Was It Something I Said!?

They must have a hoarder collector detector. Not that I would know anything about such practices, of course.

 

[JKDJedi]

The listing I won was auction style. If you were reaching out to the same seller, chances are they wanted to let the auction run its course. In this case, OBO is a competition, not a chance to get it for less than the listing price based on the seller's mood haha.

They had the one I got as auction (kellystore09), I sent them a message with an offer with the hunch they didn't know what they had. Scored. They probably set your auctions listing to automatically go up to my asking price. Or dId the "hey can you bid on this up for me"? Thing, not that I've ever done that... Either way we both SCORED!

 

[JKDJedi]

Well ... I'm keeping my day job that's for sure.. A for effort?
Half way done!

LED Bias Mod

 

[SHIMACM]

I looked on ebay and didn't find this tube being sold. Does anyone have the link?

 

[JKDJedi]

I looked on ebay and didn't find this tube being sold. Does anyone have the link?

Search the seller I posted in parentheses

 

[SHIMACM]

RCA (Cunningham) 1949 6AS7G & Tung Sol (IBM) 5998 Comparison

Preamp Tube ---> Tung Sol (Zenith) Mouse Ears 6SN7GT

Headphone used--> Beyerdynamic DT770 250OHM ( Leather Pads)


Tracks used for comparison -->

Before Your Very Eyes... (Atoms For Peace)
Streets Of Philadelphia (Bruce Springsteen)
Mi Historia entre tus dedos (Gianluca Grignani)
Creep (Radiohead)
Man Of War (Radiohead)
Has Ended (Thom Yorke)
Skinny Love (Bon Iver)



So early comparisons are that the 5998 does indeed have the higher reported amplification. To volume match both tubes I had to raise the volume on the RCA or lower it on the Tung Sol. If you own low impedance headphones the 5998 should help push them bass levels up.

The tonal signature is really hard to differentiate between the two, cudos to RCA ( with the Beyerdynamic, Sennheiser comparisons for a later date) . The Tung Sol however has the upper hand on some spots here, the cliche "full bodied" sound is here. Instruments and vocals are easily picked out, yet the RCA gels so melodiously . I like em both. The surprise here for me is the RCA, I wasn't expecting to enjoy it as much as I am now. I sent the seller a message with a huge THANK YOU!!

On some tracks it appears the RCA spreads/blends the midrange (and/or vocals) across the left to right channels. With the 5998 the vocals are more centered, more refined, almost 3d like. I can see how the RCA tubes(or 6as7g tubes in general) get this super wide description, everything gets spread out across the spectrum. The 5998 has the tighter vocal control. It's not as holographic as the RCA. Both tubes extremely enjoyable.

I use to own the later version of this RCA tube, (Mid 60's?) and do not remember them being as enjoyable as this one i have now. To stand toe to toe with the 5998 I have here is very impressive.

My RCAs are from the 60s. I'll start paying attention to I can find some of those from the 40s. It's really nice to compare Ts vs RCA. Will the RCA together with Ken Rad give Beyer more body? Maybe I can match with TS.

 

[JKDJedi]

My RCAs are from the 60s. I'll start paying attention to I can find some of those from the 40s. It's really nice to compare Ts vs RCA. Will the RCA together with Ken Rad give Beyer more body? Maybe I can match with TS.

RCA will do fine.

 

[JKDJedi]

so apparently the LED are direction specific... great.. have to tear her apart again..lol.. only getting one channel playing here X(