Finally found time to check the bank of 4 220uf caps for a voltage value which is 385v. So it appears my theory of the tx being 12 or 15v on both secondaries was incorrect.
Having visited my local electronics shop (before checking the caps) the owner could only find chassis mount txs with the same voltage on each secondary which may point to my tx being custom made for Glenn Croft ?
Thankyou for the circuit diagrams of the Vita and Supermicro, the latter bears very close resemblance to my Vitale except the Supermicro has an ecl85 presumably for regulation. The Micro, I believe, (without valve regulation) was the forerunner to the Vitale. The filament power supply section is the same suggesting Walter’s recommendation of 15v secondary is correct and possibly 230 - 250v to supply the ht section. As there is sufficient space inside the Vitale would a toroidal, if available, with the correct secondary voltages be a step in the right direction ? Or even 2 mini toroidals one for each circuit ?
Please be assured I’m very aware of the dangers of electrocution being an Electrician for many years I have a healthy respect for mains voltages. If 1 or 2 txs are required I’m confident of being able to safely install.
David.
PS An earlier response questioned why the tx had blown initially, which happened after the Vitale was switched on and off several times while moving it to swap cd players. Also following a telephone conversation with an ex Croft stockist he said Glenn had a faulty batch of txs a few years ago around the same time my Vitale was returned to him for the selector switch to be replaced. Glenn also slightly upgraded the amp but apart from the original red lamp inside the amp being removed (possibly to do with voltage regulation) I don’t recall exactly what he did but maybe the tx was also swapped ?
Apologies for the lengthy post but I’d really like to repair the Vitale which has a superb phonostage that easily outclassed all my previous pres. 🙂
Having visited my local electronics shop (before checking the caps) the owner could only find chassis mount txs with the same voltage on each secondary which may point to my tx being custom made for Glenn Croft ?
Thankyou for the circuit diagrams of the Vita and Supermicro, the latter bears very close resemblance to my Vitale except the Supermicro has an ecl85 presumably for regulation. The Micro, I believe, (without valve regulation) was the forerunner to the Vitale. The filament power supply section is the same suggesting Walter’s recommendation of 15v secondary is correct and possibly 230 - 250v to supply the ht section. As there is sufficient space inside the Vitale would a toroidal, if available, with the correct secondary voltages be a step in the right direction ? Or even 2 mini toroidals one for each circuit ?
Please be assured I’m very aware of the dangers of electrocution being an Electrician for many years I have a healthy respect for mains voltages. If 1 or 2 txs are required I’m confident of being able to safely install.
David.
PS An earlier response questioned why the tx had blown initially, which happened after the Vitale was switched on and off several times while moving it to swap cd players. Also following a telephone conversation with an ex Croft stockist he said Glenn had a faulty batch of txs a few years ago around the same time my Vitale was returned to him for the selector switch to be replaced. Glenn also slightly upgraded the amp but apart from the original red lamp inside the amp being removed (possibly to do with voltage regulation) I don’t recall exactly what he did but maybe the tx was also swapped ?
Apologies for the lengthy post but I’d really like to repair the Vitale which has a superb phonostage that easily outclassed all my previous pres. 🙂
Attachments
But near your area there isn’t a trafo manufactures?
I have here in Italy a friend company who makes trafo under request also toroid with a central hole resinated and a resinated feet to fix strongly to the chassis
But the cost of spedition and taxes are high I suppose
In every case you need, as told, two sec
15 volt 1,5A
220-230 vac 100mA minimum
I have here in Italy a friend company who makes trafo under request also toroid with a central hole resinated and a resinated feet to fix strongly to the chassis
But the cost of spedition and taxes are high I suppose
In every case you need, as told, two sec
15 volt 1,5A
220-230 vac 100mA minimum
Today I took the faulty tx to Trans-Tronic Ltd in Chesterfield about a mile from my home. Spoke to a helpful chap named Alex who advised the item could be rebuilt to original spec’. He also surprisingly said they had built transformers for Croft Acoustics in the past !
He advised that one secondary was 15v and the other 260v but was unsure of ma rating although that can apparently be deciphered once the tx is stripped. I have asked for the tx to be rewound & repaired at their earliest opportunity so the Vitale should be back to good health very soon. 🙂
Thankyou to all the people who took time to reply to the initial request, your input is much appreciated.
David.
He advised that one secondary was 15v and the other 260v but was unsure of ma rating although that can apparently be deciphered once the tx is stripped. I have asked for the tx to be rewound & repaired at their earliest opportunity so the Vitale should be back to good health very soon. 🙂
Thankyou to all the people who took time to reply to the initial request, your input is much appreciated.
David.
Hi all,
Update on the replacement transformer. After the initial discussion with Trans Tronic saying they could strip and rebuild my faulty tx two days later they emailed to say it would be £250 + vat 👀.
So I decided to have a toroidal custom built by an EBay seller in China (with excellent feedback) for a third of the cost. I specified the 15v 1.5amp and 260v 100ma secondaries and 230v primary as recommended and today it has arrived.
A couple of questions; The original chassis mount tx had a 0.047uf X2 suppressor across the primary, is this required with the new toroidal ? Also on the wiring instructions there is a 3rd wire (green) on the primary side labelled as SCR, which I’m assuming is to be connected to earth ? And finally is the existing 500ma slow blow in line fuse sufficient ?
Thanks,
David.
Update on the replacement transformer. After the initial discussion with Trans Tronic saying they could strip and rebuild my faulty tx two days later they emailed to say it would be £250 + vat 👀.
So I decided to have a toroidal custom built by an EBay seller in China (with excellent feedback) for a third of the cost. I specified the 15v 1.5amp and 260v 100ma secondaries and 230v primary as recommended and today it has arrived.
A couple of questions; The original chassis mount tx had a 0.047uf X2 suppressor across the primary, is this required with the new toroidal ? Also on the wiring instructions there is a 3rd wire (green) on the primary side labelled as SCR, which I’m assuming is to be connected to earth ? And finally is the existing 500ma slow blow in line fuse sufficient ?
Thanks,
David.
Yes to capacitor, yes if the screen is a safety isolating one, and yes to the same fuse value (initially) but I have read that toroidals draw a higher switch on current so that needs to be considered.
Ok thanks Logic, will fit the suppressor across the primary and scr to earth, it is yellow and green striped after all 🙂 Fingers crossed the 500ma fuse is up to the higher in rush current of the new toroidal 🤞
Today the transformer has been installed as per the instructions, so with trepidation the Croft was reinstalled into my system driving a World Audio Design K5881 power amp and switched on. Success 😊 sweet sounds have been restored !
One thing quite noticeable when no music is playing is the reduction of background hum which can now only just be heard with an ear 6 inches from the speakers (Focal 816V having 92db efficiency) whereas with the previous tx it was just about audible 2 feet away. So the toroidal sounds to be an upgrade over its predecessor 🙂
Excellent customer service from HiFi Original Audio (Ebay name - wolf6911) in China who suppled the custom wound tx and delivered it within 10 days at a cost of £90 including vat and import duty.
Looks like it could be a late one tonight 🍺
Thankyou to all who offered their advice 👍.
One thing quite noticeable when no music is playing is the reduction of background hum which can now only just be heard with an ear 6 inches from the speakers (Focal 816V having 92db efficiency) whereas with the previous tx it was just about audible 2 feet away. So the toroidal sounds to be an upgrade over its predecessor 🙂
Excellent customer service from HiFi Original Audio (Ebay name - wolf6911) in China who suppled the custom wound tx and delivered it within 10 days at a cost of £90 including vat and import duty.
Looks like it could be a late one tonight 🍺
Thankyou to all who offered their advice 👍.