Recently upgraded to the Micro 25 RSLS from 25R

[Novemberman]

Hello ,
I’m a fairly member to this forum though I’ve been reading and enjoying it for years . I actually discovered Croft gear ( and I’m very thankful I did ) many years ago by accident after reading posts made about Croft on this forum .I just recently upgraded from my much loved 7 year old Micro 25R to the Micro RSLS . It’s only been a couple of days, but I’m already thrilled with the upgrade . Just wondering if any of you Croft Micro 25 RSLS owners have experienced a further improvement in sound after the RSLS has had a few more weeks of extensive running in . Greetings from Canada

[Thing Fish]

Hi Drew, like you I recently upgraded from a 25R to a RSLS (used) that had also been tweaked further by Glen (to it's limit apparently)
I was amazed at the difference in detail it gave me over the 25R.

I can't directly answer your running in question but other amps I have bought from Glen certainly improved over time.

Changing the tubes also gives a pleasing upgrade.

[Novemberman]

Thank you for responding Dave . Would you mind sharing with me which array of tubes you’re using ? I realize it’s all subjective . In my previous Micro 25R I was using all Sovtek 12ax7 LPS with fabulous results . Markedly superior to the stock JJ’s imo . Unfortunately, when Glenn shipped my upgraded RSLS , UPS lost the shipment! I was just sick about it . Thankfully Glenn was was very kind to build me a replacement FOC but all of my Sovtek tubes were lost . I believe my new replacement RSLS has some Telsa and JJ tubes . I plan on replacing them - just not sure with what ? Any suggestions would be appreciated

[Jimbo]

Hi Drew, Interesting reading your experience upgrading from the 25R to 25RS LS. I currently run an upgraded 25R which has the line stage from the RS but without the separate PSU. I am considering upgrading to the spec you have sometime in the future.

Regarding Tube recommendations I would try some NOS Tesla. Any from the 1970s will sound superb and are way better than JJ Tesla and in fact the Tubes I currently own which are Tesla ECC83 32 sound to my ears better than anything else I have tried my quite a margin. However I use these only in the phono stage. I use NOS Brimar in the Line stage with great results.

What tubes are you currently using in your Line stage section?

[walpurgis]

Hello Drew. Welcome to AOS.

Plenty of Croft fans here.

Join in any chat that interests you, there's a lot going on and it's a friendly place.


Enjoy the forum,
Geoff.

[Novemberman]

Hi Drew, Interesting reading your experience upgrading from the 25R to 25RS LS. I currently run an upgraded 25R which has the line stage from the RS but without the separate PSU. I am considering upgrading to the spec you have sometime in the future.

Regarding Tube recommendations I would try some NOS Tesla. Any from the 1970s will sound superb and are way better than JJ Tesla and in fact the Tubes I currently own which are Tesla ECC83 32 sound to my ears better than anything else I have tried my quite a margin. However I use these only in the phono stage. I use NOS Brimar in the Line stage with great results.

What tubes are you currently using in your Line stage section?

Hello ,
Thank you, I’ll investigate . I’ve just received my RSLS so I’m just using the Tubes supplied by Glenn . I’ve never purchased NOS tubes before . Trying to find a good NOS tube seems like it could be rather complicated and a bit of a slippery slop. .It can be rather confusing for a novice like me as there seems to be a lot of conflicting opinions out there .Are there some reputable and helpful NOS dealers you’d recommend ?

[Novemberman]

Thank you Geoff - much appreciated.

[Novemberman]

Hi Drew, Interesting reading your experience upgrading from the 25R to 25RS LS. I currently run an upgraded 25R which has the line stage from the RS but without the separate PSU. I am considering upgrading to the spec you have sometime in the future.

Regarding Tube recommendations I would try some NOS Tesla. Any from the 1970s will sound superb and are way better than JJ Tesla and in fact the Tubes I currently own which are Tesla ECC83 32 sound to my ears better than anything else I have tried my quite a margin. However I use these only in the phono stage. I use NOS Brimar in the Line stage with great results.

What tubes are you currently using in your Line stage section?

Hi Jimbo , According to the Brimar website, they unfortunately don’t deliver to we here in Canada . I’ve read a lot of positive comments about NOS RCA black and grey plate 12hb7 tubes - any thoughts ?

[Jimbo]

Hi Drew,

It is tricky trying to recommend sources for NOS tubes but I am sure there are plenty of good suppliers in the USA? Obviously Ebay is a large source of Tubes but knowing the quality and authenticity of what you are buying is not always certain? Maybe approach a few of the large Tube suppliers and ask what they have, sometimes they have tubes that may not always be advertised.

Other than that keep an eye open on the forums and indeed this forum as both Tesla tubes and Brimar tubes have been sold here. In fact there were some fantastic value Tesla tubes available recently in the classified section.

[Novemberman]

Hi Drew,

It is tricky trying to recommend sources for NOS tubes but I am sure there are plenty of good suppliers in the USA? Obviously Ebay is a large source of Tubes but knowing the quality and authenticity of what you are buying is not always certain? Maybe approach a few of the large Tube suppliers and ask what they have, sometimes they have tubes that may not always be advertised.

Other than that keep an eye open on the forums and indeed this forum as both Tesla tubes and Brimar tubes have been sold here. In fact there were some fantastic value Tesla tubes available recently in the classified section.

Thanks Jimbo - appreciate your feedback . Drew

[Novemberman]

Hi Drew,

It is tricky trying to recommend sources for NOS tubes but I am sure there are plenty of good suppliers in the USA? Obviously Ebay is a large source of Tubes but knowing the quality and authenticity of what you are buying is not always certain? Maybe approach a few of the large Tube suppliers and ask what they have, sometimes they have tubes that may not always be advertised.

Other than that keep an eye open on the forums and indeed this forum as both Tesla tubes and Brimar tubes have been sold here. In fact there were some fantastic value Tesla tubes available recently in the classified section.

Hi Jimbo ,
Well , I’ve rolled the dice and purchased my first ever NOS tubes . I purchased 2 matched 1960 NOS RCA black plate 12bh7a tubes to replace the 2 stock JJ ECC99 tubes in my new RSLS . The dealer seems reputable but time will tell . I haven’t received the NOS yet , but in the meantime my RSLS actually sounds awesome with the Croft supplied stock JJ’s. Glenn Croft is some kind of magician .
Best ,
Drew

[walpurgis]

How long do valves have to be 'warehoused' before they become NOS? Surely the popular choices must be getting thin on the ground...........or is somebody manufacturing new fake NOS? (yes, I know it is alleged to happen)

[Jimbo]

Glad you are getting great performance from your RSLS with stock JJ Tesla valves, it should move up another level with NOS RCA Black plate 12BH7a. I will be using one of those myself in my 25R line stage.

Interesting I found JJ valves sounded fine in regulation stage but not the phono stage. NOS Tesla were far better in this position.

[Novemberman]

Glad you are getting great performance from your RSLS with stock JJ Tesla valves, it should move up another level with NOS RCA Black plate 12BH7a. I will be using one of those myself in my 25R line stage.

Interesting I found JJ valves sounded fine in regulation stage but not the phono stage. NOS Tesla were far better in this position.

Hi Jimbo ,
I received and installed my NOS RCA Black Plate 12bh7a tubes . What a huge up tick in performance the NOS tubes bring the the RSLS - quite shocking actually . Ultra vivid and clear - solo instruments sound huge coming out of my little Falcon Gold Badge Ls35a speakers. It almost sounds like I’ve installed a much more powerful amp . I’m amazed

[Jimbo]

Hi Jimbo ,
I received and installed my NOS RCA Black Plate 12bh7a tubes . What a huge up tick in performance the NOS tubes bring the the RSLS - quite shocking actually . Ultra vivid and clear - solo instruments sound huge coming out of my little Falcon Gold Badge Ls35a speakers. It almost sounds like I’ve installed a much more powerful amp . I’m amazed

Excellent Drew and good choice of 12BH7a, I use the very same one in my line stage and the difference as you say is shocking. It produces the same vivid/clear sound I get through my NOS Teslas in the phono stage. The extra boost you have to your perceived power output maybe the fact the RCA tests very well and is performing at the top of its output range?