Hi all I have a pair of Cary Audio 300b se mono blocks. I need to replace the transformers, cary wants a lot of money for theirs, I was wondering if anyone out there knows of a transformer that will work as a replacement, Thanks in advance Thurston
Most of the transformer winders such as Lundahl, Hammond, Edcor, etc. offer OPT's for the 300B. You may also try the Swap Meet forum to see what's on offer.
Do you need O/P "iron" or power "iron"?
A chart of 300B operating conditions sets is here. Please notice that 3000 to 3500 ohm O/P primary impedance fits many situations.
Quite a few Cary amp designs badly abuse vacuum B+ rectifiers. Please post or link the schematic of the monoblocks in question.
A chart of 300B operating conditions sets is here. Please notice that 3000 to 3500 ohm O/P primary impedance fits many situations.
Quite a few Cary amp designs badly abuse vacuum B+ rectifiers. Please post or link the schematic of the monoblocks in question.
You haven't said which transformers need replacing, power or output? Or how you came to a situation where they need to be replaced.
Replacing transformers will not increase output power if this is what you are thinking.
Transformers of comparable quality will not be inexpensive, and may also not have the proper form factor.
If you ever intend to sell these amplifiers on, with non Cary transformers the resale value will be just about zip, if you don't then it probably is not an issue.
Replacing transformers will not increase output power if this is what you are thinking.
Transformers of comparable quality will not be inexpensive, and may also not have the proper form factor.
If you ever intend to sell these amplifiers on, with non Cary transformers the resale value will be just about zip, if you don't then it probably is not an issue.
I need to replace the CT114 transformers, I discovered there was no high voltage on the plate of the 300B tube. Upon further investigation, I find the output transformer to be bad. The high voltage supplied to the 300B tube is first run through the primary side of the output transformer, then fed to the 300B tube plate. One of the wires associated with this high voltage feed was right next to the 5U4 tube socket, pressed directly against one of the pins, and eventually caused a short. This caused a very high current to run through the output transformer primary, burning out that primary internally. This blue wire was not very well placed during manufacture, and finally failed. Cary said they do not stock this transformer anymore but can replace it with a ct 116 which the costs would be $210.75 ea these are sold un potted if you need them potting with new transformer cans its;
· $60.00 ea. which includes wax and labor.
· $75.00 ea. New transformer cans
· $10.00 ea. Label on top of cans
If you don’t need the above then it’s $210.75 ea. and I need to replace the transformers in both mono blocks.
· $60.00 ea. which includes wax and labor.
· $75.00 ea. New transformer cans
· $10.00 ea. Label on top of cans
If you don’t need the above then it’s $210.75 ea. and I need to replace the transformers in both mono blocks.
What does the failed "iron" look like? A photo will be of considerable help. See Kevin's form factor remark.
Meaningful advice can't be supplied in the absence of a schematic. What is the budget for this salvage project? Obviously, it's NOT unlimited.
Meaningful advice can't be supplied in the absence of a schematic. What is the budget for this salvage project? Obviously, it's NOT unlimited.
I asked Cary for a schematic and they charged me $25. and sent the wrong one, I am now trying to get the correct one from them
Replacing the PT requires you know what the specs for the originals. In lieu of that you will need to have a schematic to "reverse engineer" the specs. Hammond, Edcor, etc, all will make you a PT to suit your needs but more info is required.
I don't understand why you need to replace the trannies on both monos if only one is blown.
I don't understand why you need to replace the trannies on both monos if only one is blown.
I have requested a schematic from Cary and they charged me $25. and sent the wrong one, Cary suggested if I replace the burned out one with their CT116 and than I should also replace the other with the same CT116 so they match , that is why I was trying to figure out if it is possible if I can get away with just replacing the burned out one
I would buy a pair of james JS-6135HSF-2 OPTs instead of the originals.
I bet they sound better. You've got only four wires to solder. The only
question is are you willing to drill the chasis in order to mount the transformers.
You also need to make sure they fit in.
I bet they sound better. You've got only four wires to solder. The only
question is are you willing to drill the chasis in order to mount the transformers.
You also need to make sure they fit in.
Take a picture of the area of the amp where the output transformer
is connected to the last capacitor of the power supply (Its probably the closest capacitor to the OPT and the 300B tube) and we'll try to help you.
You need to solder:
from the last capacitor + leg to the OPT primary B+
from OPT primary output to the tube Anode
Then solder the two OPT secondary legs to the speaker terminal.
is connected to the last capacitor of the power supply (Its probably the closest capacitor to the OPT and the 300B tube) and we'll try to help you.
You need to solder:
from the last capacitor + leg to the OPT primary B+
from OPT primary output to the tube Anode
Then solder the two OPT secondary legs to the speaker terminal.
Sounds to me like the failure was due to Cary assembling the amp incorrectly.
That being said I had a Cary SP-103 ( I think ) hybrid preamp that started to hum after 9 months. I contacted Cary and they sent me instructions on how to turn down the gain which is what they claimed was normal after break-in. I opened it up and when I turned down one pot it cracked and broke. I figured it's under warranty and I'll have to send it in so I tried adjusting the other channel. Same thing. When I sent it in the service tech scolded me for attempting this adjustment and that I should have sent it in without touching it. I explained the instructions I received and then he said that some of them were glued once a final adjustment was made. So he replaced the pots and s not it back. It still had a horrible hum. The service said he just replaced the pots and didn't make any other repairs because he thought all he was supposed to do was replace the pots. So I sent it back. A few weeks later I got it back with the same bad hum. I was prepared to drop drive to NC to personally take care of the problem. The customer service guy told me he would be be willing to upgrade me to their all tube preamp...one that was $4000 more. I told him i'd willing to take the new SP-100 preamp as an exchange. I accepted and luckily it's been trouble free so far. Quite frankly because of my experience I'd choose a different company if I were to buy a factory assembled piece of audio equipment.
That being said I had a Cary SP-103 ( I think ) hybrid preamp that started to hum after 9 months. I contacted Cary and they sent me instructions on how to turn down the gain which is what they claimed was normal after break-in. I opened it up and when I turned down one pot it cracked and broke. I figured it's under warranty and I'll have to send it in so I tried adjusting the other channel. Same thing. When I sent it in the service tech scolded me for attempting this adjustment and that I should have sent it in without touching it. I explained the instructions I received and then he said that some of them were glued once a final adjustment was made. So he replaced the pots and s not it back. It still had a horrible hum. The service said he just replaced the pots and didn't make any other repairs because he thought all he was supposed to do was replace the pots. So I sent it back. A few weeks later I got it back with the same bad hum. I was prepared to drop drive to NC to personally take care of the problem. The customer service guy told me he would be be willing to upgrade me to their all tube preamp...one that was $4000 more. I told him i'd willing to take the new SP-100 preamp as an exchange. I accepted and luckily it's been trouble free so far. Quite frankly because of my experience I'd choose a different company if I were to buy a factory assembled piece of audio equipment.
Yes that was my assumption also, my experiences with Cary Audio has not been very positive, I probably will stay away from them in the future also, these mono blocks were sent back to them 2 years ago and were re capped, and updated to the signature model, but the service was not great, they left many questions un answered.
IMO, staying away from Cary makes sense.
Edcor's CXSE25-3K is a "budget" replacement for the damaged trafo. Obviously, you need to buy a pair, but Edcor's stuff rates to be the least costly way to end up with matched monoblocks. I would not be shocked if little (perhaps no) sonic degradation, when compared to the OEM "iron", occurs. The "iron" from James will be better and cost it too. TANSTAAFL.
Another option is to send both O/P transformers to Heyboer for reverse engineering and rebuilding. Query them about costs.
Edcor's CXSE25-3K is a "budget" replacement for the damaged trafo. Obviously, you need to buy a pair, but Edcor's stuff rates to be the least costly way to end up with matched monoblocks. I would not be shocked if little (perhaps no) sonic degradation, when compared to the OEM "iron", occurs. The "iron" from James will be better and cost it too. TANSTAAFL.
Another option is to send both O/P transformers to Heyboer for reverse engineering and rebuilding. Query them about costs.
Single ended output trans are mostly uncomplicated unlike some PP OPTs but you could send the burnt out one to Heyboer and a few other places and they will rewind the exact same thing on the old frame. They can probably repot for you if yours is potted. I would think that the magnet wire would be the same and they would match up the specs for you. the cost would probably be the same or less than a new one. something to consider. But if you are a really picky type of person then you might as well break down and spend for 2 new OPTs or the idea of have 2 that were not made at the same time or wound by the same company will drive you crazy. cheers.
The rightmost picture shows the rectifier tube socket connected to the power transformer yellow wires(5U4 cathode legs 2 &8) and red wires(5U4 anode legs 4 & 6). I Cant figure out from these pictures which is the last B+ capacitor.
When the defective transformer was connected, the two secondary wires were connected to the speaker terminals so with the new transformer you'll
do the same. About the primary wires they should be connected like in the picture below.
Attachments
If you have even the slightest thought of selling the Cary amps in the future, you should get the Cary transformers. You could pay less buying another brand (you could also pay a lot more), but anything other than a Cary will destroy the resale value. There is also a practical problem with installing a non-Cary transformer---you will probably have to drill new mounting holes, and the Cary chassis is rather thick steel so this is not an easy task.
- Status
- Not open for further replies.