Dear Pindac, perhaps you had not seen my question prior to your most recent post, but I asked what two vintage brands of 6SN7 you preferred over the KR.
Tube rolling in Hagerman Trumpet MC
I have been doing some tube rolling in the Trumpet MC and am trying to be a sure as I can that I don't substitute a tube that could cause a problem.
It looks like from my very poor reading of the schematics that the V1 12ax7's are for initial gain pre RIAA, the second pair V2 are phase splitter post RIAA, and the 12au7's V3 are driver/output/cathode follower (not sure about that last one as the circuit doe not look like a typical cathode follower circuit and even looks like anode follower?). Any enlightenment here would be helpful. This is because even tubes that are considered "drop in" substitutes are not actually identical on the manufacturer spec sheets. For instance the 5418 has a slightly higher heater current than and au7 and there might be another parameter that is different (Vhk?). Even the 7316 is slightly different. And of course the 5751 has lower gain than a ax7 as well as other differences. Many of the differences are still within spec, and given what I can see from the online schematic of the Trumpet MC, look like no problem, but I just want to make sure. I have emailed Jim Hagerman and he has been helpful when I have, but I hate to keep bugging him with my questions, so I will bug you guys instead.
Thanks for you help and the bandwidth.
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@lewm At my end, I have kept my experience had, tightly focused on the knowledge the assessment of the KR Black VR231 and other Valves used, were when in use on my Power Amp's Circuitry ( Bespoke Design - Commission Built 845 Monoblocks). It is not possible for me to suggest, my findings will Transfer across other circuits, hence I am not keen to offer up Brand / Model of Valves. The Two Valve Brand / Models that have been the most impressive when carrying out the comparisons, are when sought out as a sale item not cheap as a matched pair, these can easily be discovered at £300 - £500 as a common price. For this reason, I don't want to plant seeds that might encourage a individual to consider these Valves, especially if they can't immediately learn what they have bought resting wise, following the delivery. Another very valid reason for my not sharing info, that others observing might have expressed a scant interest in learning, is to do with how was able to have the experience being reported on. Those who are assisting me with what I do in relation to Audio, know the forum used and pseudonym attached to me. If they don't choose to join and share their account, I take it there is a want to remain that way. There is also the IP shared with me, that is always considered by myself. When a person takes the time to share with myself, what is learnt by themselves through long-term dedication to a interest, this is a gift to me, which I am confident is passed on the understanding it is not to be widely shared. In relation to the two Valve Brand / Models, these ones are not typically referenced when Vintage Models are discussed openly, possibly there is scarcity? It is not for me to become a Public Broadcaster of valuable info shared with me. Such reveals being offered are the results of the trust formed in the friendship. I can quite happily share, after all the positives I encountered on the Gon's Linlai E 6SN7 Thread, I have now got a Pair of these on route to learn how these compare to the KR's and the other Two Brands, when used in my Power Amp' Circuit and the New Pre Amp that is being produced circuit. Also for inquisitive reasons only, as certain configurations of Valves will extend beyond my budget, but does appeal, is that the Valves that will be loaned from my friend for the comparisons when the Pre Amp is finished. Will enable the KR's and the other Two Valve Brands to be used as extremely close matched Quad Sets. Enabling them to be used in conjunction as Quad Sets in both Pre and Power Amp's. What's not to like about such a option on Matched Sets and the available permutations. My hope being the Linlai E 6SN7 has a synergy in one of the permutations that makes them keepers, either with the owned KR's or other owned 6SN7's, or loaned Valves as a future option. All a bit crazy as a undertaking when I am also bringing into the Audio System SS Power Amp's to be tried out against the Valve Power Amps using the New Pre Amp and other owned and loaned Pre's. Today, based on not too far gone and more recent experiences. I have witnessed changes within the SS Power Amp's designs that are being Marketed. Which has been extremely profound in the impact made and my becoming confident in the knowing that options are there, for acquiring a SS Power Amp' that really competes with high end Valve Amp's, where SS Power Amp's can be purchased for less monies than a Particular Brands Vintage Quad set of 6SN7s or their equivalents. This calculation of costs gets even more noticeable when allowing for the cost of Output Valves as well. There it is, more expression of what can be referred to as a 'pindac' idiosyncrasy.
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- 61 posts total