Rolling Mullard 6DJ8 into GE 5670 Application

The adapter was delivered last night and I was able to do the tube swap this morning.  It definitely sounds different and my initial response was positive, but I'm becoming less impressed as time goes on.  I'll give it a few weeks and then switch back and see how it feels.

I have early 1960's E88CC Tubes in a DAC as a result of Tune Rolling Exercises and can't get enough of the sound on offer.  

Even now when putting all the HiFi equipment into Storage, it is the DAC > Transport that will be the last Source Equipment to be packaged, I like it to be at hand to be used.

I treat Vintage Valves like a Cartridge, the Values can be high, and there is about a 1000ish hours if all goes well of useful output, even though longer usage can be achieved. My choice of Valves for the DAC has been the same choice for a Friends CDP, and they have an exceptional option from their vast collection of Tubes.

I also have a Hybrid Phon' with Burson Vivid Op Amp's and another Brand of Early 60's Vintage E88CC's. Once more as a result of a Tune Rolling exercise, the DAC's Tubes did not show themselves of in the same manner when used in the Phon's circuit.

Keep options open on Tubes certain circuits can really allow a particular Tube to rise above others in perceived attraction during a period of Tube Rolling.

I can get adaptors and use my 6SN7 collection in place of the E88CC Tubes to see where there are new experiences to be discovered.

I know I sound pedantic, but the 6SN7 and E88CC are very different tubes electronically, even if you can find an adapter to make a 6SN7 "work" in a socket wired for an E88CC. The E88CC is a high transconductance tube with a mu of 33. The 6SN7 is a medium mu tube (mu about 16) that usually is run with less than 12mA of plate current, usually much less in fact. The E88CC likes more like 15mA of plate current. Also, because of its high transconductance, the conditions that work for the E88CC could conceivably be destructive for the 6SN7 over a short period of time. If you have a schematic, and if you know how to modify the circuit parameters to suit the 6SN7, then that’s fine. Otherwise, I would leave well enough alone. If the tube is serving as a cathode follower in the DAC, the E88CC is actually a better cathode follower than the 6SN7 (because of characteristics mentioned above and other characteristics), which would be another reason to leave it alone. Of course, you can do whatever you want; I am only giving you some facts to think about.

It is important to Flag Up a foreseen risk, if one believes it is present.

For anybody who has a knowledge an adapter socket is available and can be used to use a 6SN7 in place of a E88CC, @lewm has made a good information available to be heeded. 

From my end I don't do EE, I step sideways and allow others their opportunity to shine. When the EE extends to my HiFi System the sideways step is enlarged and the work is offered to a select few. 

I have been a social active individual within HiFi for too many years now, and would not change this, I see it as the future for the Hobby.

A Forum is a broad form of communication but is no substitute for face to face and being ears on when experiencing HiFi related products.

I have met with some very influencing individuals who are adept in their Skills for producing sound, some with a career extending over 40 years, specialising in designing / building devices to produce / manage sound.

I am no contender to these individuals; I trust in their work more than I do the mainstream and am fortunate to have developed relationships where contact is always available and visiting them is encouraged even though irregularly maintained.

This all adds up to where I am with a system, the Devices that are the entirety are Bespoke bar One Device. I am using the following: Cart' (Custom Built Design) > Yonearm (Bespoke Modified) > 2 x SUT's (Bespoke Built) > Head Amp (Bespoke Built) > 2 x Phonostages ( One Bespoke Built and One Bespoke Modified) > DAC (Bespoke Design) > Pre-Amp (Bespoke Design and Ongoing Build) > Power Amps (Bespoke Design and Build).

Additional to the above the certain items of Valve Equipment has undergone evaluation of selected components and my selected parts resulting from demonstration impressions made are the ones in use.

Later down the line Tube Rolling was the next avenue of investigation.

The Designer / Builders were given a list of Valves being proposed by a friend with an extensive collection of tubes, that were to be offered for loan to carry out Tube Rolling.

On the approval of the designer for the Valves listed, matched Valves were made available for the Tube Tolling experience.

In relation to the 6SN7, the designer made it known certain Valves that should not be used. 

To have the surrounding support as is on offer, is a very fortunate place to be and I am forever grateful. 

At present the HiFi System is as good as packed away for storage.

When brought out for use once more and is set up in a Room that allows it to deliver to the standard it has been able to, I will get back on track with revisiting equipment discovered over the past year or longer, to satisfy my curiosity for how certain items of equipment will work within my system, as a result of the good impressions made during demonstrations within another system.

I will also be revisiting the 6SN7 idea and seeking out the information from the designer to learn if the method proposed is able to function without any concerns. This is important for me, as when doing a home demo' I do like to experience a newly added device in a variety of configurations.

For instance, when the Nano Core Transformers are used as the first of a selection of Home Demo's, I will be looking to experience these with a selection of owned Valves, Cartridges and Cables.

Such exchanges being undertaken are easy for myself to achieve, as I am well versed and 'hands on' in such matters.

What will be present as always is, is the pre-discussions about the proposed methods with the correct source for the information and working for the benefit of the system. I don't go in blind; I take all advisories given seriously. I look after these special devices, concerning myself for their maintained condition with a vigilance.

  As an aside to the above, but keeping with the subject about being careful and taking advisories seriously.

The following will be more of a familiar day to day occurrence than my practices.

A friend who I trust in relation to the Vinyl LP as a Source more than anybody I know, many ears past informed me the Cue Lever is best used to control the Needle Drop and not just push the Lever Down and Trust in the rest.

I took the advisory on board and have maintained a version of this method to this day. I have even developed the habit where I suspend the Styli, a miniscule distance from the LP. This practice speedily reveals if the LP has Static or if a contamination is on the Styli, as the interference being produced if something is present, is an audible sound from the Speaker. 

The days of Landing the Styli on the outer rim Deadwax and 'willing it' to travel in toward the lead in grooves with a 'skipping heartbeat', are a thing of the forgotten past.

There have been wins for myself, through having been willing to make changes to how a cue occurs for a Needle Drop, I'm sure many are now unknown to me, as I don't believe I had met with all scenario's that could occur.

The Tonearm Lifter used as the Styli enters the inner Deadwax Grooves is one more device that has proved to offer 'peace of mind'. 

Not too long ago, my friend who gave ne the above advisory, was placing an Album to be played and at the time of the cue become distracted momentarily.

They used the older less controlled method and pushed the Lever Down in one operation, trusting in their Cart' alignment. The outcome being a £4000ish Cart' with very few usage hours, was needing to be returned to the Manufacturer with a Skewed Cantilever Damage.

Knowing there is a risk present from a certain method of using a Cue Lever and having consciously done something different to alleviate it occurring for a long time, has now proved to be very satisfying. 

It is not always the Cleaner, Grandchildren, Cat or Dog that are damaging a Cartridge or indenting the Speaker Cones Dust Cover.  

@lewm - Thanks for the information.  I don't know if it matters, but the adapter is allowing me to use an E88CC tube in a 6SN7 application which is the opposite scenario.

For what it's worth, it's been running since yesterday morning and so far nothing bad has happened...