View Full Version : Tube rolling in Croft amps (7R & Micro 25)
Hi All,
I've just taken delivery of a Croft 7R (thanks HiFi Dave and indeed Glenn Croft) and am running it with a Micro 25. I only listened for a few hours last night and love it (does new gear burn in ? I don't know, anyway that's not the purpose of this post !).
My plan is to make no changes and listen and enjoy as much as I can, with beer. It's a great plan :). However, I just wondered if anyone has any experience with tube rolling in these amps. and could feed back any significant differences/improvements ?
I'll come clean, I'm curious but not a great fan of tube rolling. I end up just getting frustrated. Interested nevertheless. Cheers.
Hi Ian,
See http://www.theartofsound.net/forum/showthread.php?t=13095&highlight=a2900 post 2 and others.
I have a Croft 25R and S4s and have spent much time & dollar doing just this.
Much depends on the sort of sound you are after - there is no doubt in my mind that brilliant as Glenn's amps are and stunning bang for your buck they ship with modern production valves and significant enhancements/changes are to be had by substituting good NOS valves. This is a good site for info http://www.jacmusic.com/nos/ECC83.htm but clearly there are lots of others. If you do decide to change I really do recommend going for 1950's - 70's NOS and if you buy from a reputable source quality should be fine. I bought a second hand valve tester just to be sure and I have never ended up with a duff NOS valve.
Steve
I don't know whether I want to hear this Steve ! Seriously, thanks, great response and food for thought. I do actually have a trio of Mullard ECC83s in my
Leak 20 that I can try. As I say, no rush.
Cheers.
Hi Ian,
As someone who is very experienced in both tube-rolling and listening to Croft amplifiers, my advice would be to forget all about tube-rolling just now and simply enjoy your new amp (as is), for at least a few months.
Once you are intimately familiar with what it's capable of, then, and only then, explore the possible benefits of using NOS valves. Trust me, this is very good advice!
The reason why you've found tube-rolling in the past frustrating, is because you were trying to change the sonic presentation of something you didn't fully understand, or indeed likely even know what you were trying to achieve. In effect, tweaking for the sake of tweaking....
We've all done it, though, so don't worry, just enjoy your choons for now and your lovely new amp :cool:
Marco.
camtwister
10-11-2011, 20:47
Hello Ian.
At the risk of sounding toadyish, I concur with Marco.
Having said that, if you do happen to stumble over the valves that Steve uses, namely a GE A2900 or a yellow triangle Brimar 6060 at a price that doesn't make you wince, then snap 'em up and look forward to trying them when you're versed with the signature of your new amps.
I use 5751 valves in place of the ECC83s in my Micro 25s. They have seventy per cent of the gain of the 83 and I like their presentation, which I found to be less glassy than the stock Chinese ECC83. I settled on 1950s Raytheons with windmill getters and 50s black plate five star GEs with the triple mica spacers.
Hi Ian,
As someone who is very experienced in both tube-rolling and listening to Croft amplifiers, my advice would be to forget all about tube-rolling just now and simply enjoy your new amp (as is), for at least a few months.
Once you are intimately familiar with what it's capable of, then, and only then, explore the possible benefits of using NOS valves. Trust me, this is very good advice!
The reason why you've found tube-rolling in the past frustrating, is because you were trying to change the sonic presentation of something you didn't fully understand, or indeed likely even know what you were trying to achieve. In effect, tweaking for the sake of tweaking....
We've all done it, though, so don't worry, just enjoy your choons for now and your lovely new amp :cool:
Marco.
No argument from me Marco. Sage advice - all to easy to chase the wind and end up dazed and :confused:
Tube rolling - this way lies madness :mental:
Steve
Thanks for this - in many ways it was a daft question - 'What are the benefits of tube rolling in this amp. but I don't really like tube rolling' !
I shall leave things as they are and mebbe think on when I want to muck about in the new year or something. Lovely, lovely amps.
Apologies for obsessing but just had a listen on the third day and things seem to be getting even better. I've always been a tad cynical about burn in (and usually buy vintage gear !) but this thing (7R) is quite something.
Will be putting the Micro 25 back in later this week, currently using an EE BBA.
Apologies for obsessing but just had a listen on the third day and things seem to be getting even better. I've always been a tad cynical about burn in (and usually buy vintage gear !) but this thing (7R) is quite something.
Will be putting the Micro 25 back in later this week, currently using an EE BBA.
Ian give it time..enjoy;)
jon
The Black Adder
13-11-2011, 15:42
Hi Ian,
As someone who is very experienced in both tube-rolling and listening to Croft amplifiers, my advice would be to forget all about tube-rolling just now and simply enjoy your new amp (as is), for at least a few months.
Once you are intimately familiar with what it's capable of, then, and only then, explore the possible benefits of using NOS valves. Trust me, this is very good advice!
The reason why you've found tube-rolling in the past frustrating, is because you were trying to change the sonic presentation of something you didn't fully understand, or indeed likely even know what you were trying to achieve. In effect, tweaking for the sake of tweaking....
We've all done it, though, so don't worry, just enjoy your choons for now and your lovely new amp :cool:
Marco.
+1
kininigin
14-11-2011, 14:50
Having not too long ago replaced the stock valves in my micro 25 with some 5751's and then a few days ago returning to the stock valves,im not sure where i stand on tube rolling.
I decided to revert back to the stock valves as i have added some new cables to my system and wanted to see if the slightly grainy harder presentation compared to the jan 5751 was still there.Im still not 100% sure,as i've not listened to too much music lately due to work :( but there seems to be less difference between the 2 types of valves than when i first rolled them,when there was a clear difference :scratch:.
Not sure why that would be,that's my 2 cents on the matter anyway.So in short stick with the stock for now until you 100% sure of what you have and what you want,i really should listen to my own advice :lol:
Hi Ian,
As someone who is very experienced in both tube-rolling and listening to Croft amplifiers, my advice would be to forget all about tube-rolling just now and simply enjoy your new amp (as is), for at least a few months.
Once you are intimately familiar with what it's capable of, then, and only then, explore the possible benefits of using NOS valves. Trust me, this is very good advice!
The reason why you've found tube-rolling in the past frustrating, is because you were trying to change the sonic presentation of something you didn't fully understand, or indeed likely even know what you were trying to achieve. In effect, tweaking for the sake of tweaking....
We've all done it, though, so don't worry, just enjoy your choons for now and your lovely new amp :cool:
Marco.
Ok Marco, this really was well considered and sensible advice from a bloke who knows. I cracked though ! I have a pair of Mullard ECC83s and stuck them in it and an already astonishing bit of kit got better, or more tuned to my ears anyway. A tiny bit warmer an fuller and more 'in the room'.
This may well be because the new valves it came with needed burning in, I don't know. What I do know is that I'm over the moon.
Happiest of days. The Micro 25R will be coming at some time next year, I can't not !
bikerboy
19-11-2011, 10:09
I was round at Ian,s yesterday and I was gob smacked at how the Croft and Harbeth combination worked and gelled together. They are a match made in heaven. Doug
hifi_dave
19-11-2011, 10:54
Well, Scarborough and Haywards Heath actually.:rolleyes:
Some good general advice at the end of this GrantFidelity article as well:
http://www.grantfidelity.com/site/Tube_Amp_Maintenance_setup
Some good general advice at the end of this GrantFidelity article as well:
http://www.grantfidelity.com/site/Tube_Amp_Maintenance_setup
An interesting read Skien, Cheers. This was the bit that rounded it off for me....
Sometimes we get wrapped up in the gear (the playing with the box syndrome?) and tweaking to the point where we forget what it is all about, enjoying the tunes.
:)
An interesting read Skien, Cheers. This was the bit that rounded it off for me....
Sometimes we get wrapped up in the gear (the playing with the box syndrome?) and tweaking to the point where we forget what it is all about, enjoying the tunes.
:)
Correct ;)now give the 7r a chance to settle in:eyebrows:
jon
Correct ;)now give the 7r a chance to settle in:eyebrows:
jon
OK, now I've put a Mullard in the Micro 25 I'll call it a day ;)
OK, now I've put a Mullard in the Micro 25 I'll call it a day ;)
Had my 25r pre a couple of weeks now..still running it in:eyebrows:
jon
Had my 25r pre a couple of weeks now..still running it in:eyebrows:
jon
Now that is interesting ! You've not owned the 25 and are able to compare are you John ? Or post your impressions anyway ?
Now that is interesting ! You've not owned the 25 and are able to compare are you John ? Or post your impressions anyway ?
Ian the 25 basic or 25 pre?...my First impressions are it is excellent like i said not run in yet... better to come:eyebrows:
jon
Ian the 25 basic or 25 pre?...my First impressions are it is excellent like i said not run in yet... better to come:eyebrows:
jon
The Micro 25 - just wondered what you're impressions were on the difference as I'm running one now, marvellous bit of kit.
The Micro 25 - just wondered what you're impressions were on the difference as I'm running one now, marvellous bit of kit.
Ian i do not think they will be that far apart..in the sound department..i know mine is double the price..but i do not think you got double the sound qulity:eyebrows:..and yes the are marvellous bits of kit;)
jon
Ian i do not think they will be that far apart..in the sound department..i know mine is double the price..but i do not think you got double the sound qulity:eyebrows:..and yes the are marvellous bits of kit;)
jon
Interesting John, thanks. Law of diminishing returns and all that I appreciate. I certainly can't afford the 25R upgrade at the mo' but if I spotted a s/h one I'd snap it up. It's not that I'm in any way unhappy with my new Croft gear, just wantitis really !
Interesting John, thanks. Law of diminishing returns and all that I appreciate. I certainly can't afford the 25R upgrade at the mo' but if I spotted a s/h one I'd snap it up. It's not that I'm in any way unhappy with my new Croft gear, just wantitis really !
Ian you will not go wrong upgrading to the 25r..if was not better in some departments then glenn would have not built it;)
jon
Ian you will not go wrong upgrading to the 25r..if was not better in some departments then glenn would have not built it;)
jon
Fair play John but i can't bloody afford it !
Wakefield Turntables
24-08-2014, 19:54
Back from the dead!
I've got the Croft 25 Basic. Did anyone come to a general consensus of opinion with regards the best valves for tube rolling? I've managed to find some old ECC82/3's Mullards to start with. I will have to check the dates so I dont know if they are from the fabled 50's to 70's period. Any help, comments, etc would be most welcome.
Andy
Back from the dead!
I've got the Croft 25 Basic. Did anyone come to a general consensus of opinion with regards the best valves for tube rolling? I've managed to find some old ECC82/3's Mullards to start with. I will have to check the dates so I dont know if they are from the fabled 50's to 70's period. Any help, comments, etc would be most welcome.
Andy
Seems like yesterday !
I ended up with these....
http://www.ebay.co.uk/itm/5751-JAN-GE-NOS-/260832811140?pt=UK_Sound_Vision_Valves_Vacuum_Tube s&hash=item3cbad8d884
I'll admit I didn't extensively tube roll as it sends me quite bonkers, but I very happily live with these tubes.
Wakefield Turntables
25-08-2014, 15:03
I've got some JJ ECC82/3 in mine at the mo and they are pretty cheap affairs. Saying that they certainly do the trick. I think the little Basic 25 put the Radford SCA25 preamp to shame.
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