Here are the rough pricing of the OPT's
The Hammond 1627 SE OPT -- US$200 / pair
Plitron 2.5K toroid SE OPT ---- US$450 / pair
Lundahl 2.5K SE OPT --- US$ 400/pair
Tamura 2.5K PermAlloy OPT --- US$ 840/pair
Johnny
The Hammond 1627 SE OPT -- US$200 / pair
Plitron 2.5K toroid SE OPT ---- US$450 / pair
Lundahl 2.5K SE OPT --- US$ 400/pair
Tamura 2.5K PermAlloy OPT --- US$ 840/pair
Johnny
I can spend on it around 2K HKD.
Do you know the quality of OPT from china ?
If 300B SE as output stage , what the optimal primary impendence of OPT require ?
Do you know the quality of OPT from china ?
If 300B SE as output stage , what the optimal primary impendence of OPT require ?
If your budget is only HK$2K, seems Hammond 1627 is the choice.
The primary impedance of OPT for 300B should be within 2.5 to 3.5K.
I don't know much about the Chinese made OPT's except the James transformer from Taiwan seems to be quite good indeed.
Is your name Wong Chi Kwong? He is my classmate in HK Poly.
JOhnny
The primary impedance of OPT for 300B should be within 2.5 to 3.5K.
I don't know much about the Chinese made OPT's except the James transformer from Taiwan seems to be quite good indeed.
Is your name Wong Chi Kwong? He is my classmate in HK Poly.
JOhnny
Thanks for your comments.
My name is Wong, Chi-Keung. A little bit different to your classmate.
You also call me CK as well.
James, I have found that the price about 2.5K to 3K HKD. But nobody tell me the feeling use it.
My name is Wong, Chi-Keung. A little bit different to your classmate.
You also call me CK as well.
James, I have found that the price about 2.5K to 3K HKD. But nobody tell me the feeling use it.
Hammond's distributor in HKG
I check Hammond's web site. Here is their distributor in HKG.
Farnell-Newark InOne
Registered Office
Unit B, 12th Floor, Entertainment Building
30 Queen's Road Central
HONG KONG
Tel: 800 968 280 or +65 788 0200
Fax: 800 968 480 or +65 788 0300
www.farnellinone.com
By the way, the phone/fax numbers seems a bit strange to me. Of course, you can easily find their phone number from phone book.
JOhnny
I check Hammond's web site. Here is their distributor in HKG.
Farnell-Newark InOne
Registered Office
Unit B, 12th Floor, Entertainment Building
30 Queen's Road Central
HONG KONG
Tel: 800 968 280 or +65 788 0200
Fax: 800 968 480 or +65 788 0300
www.farnellinone.com
By the way, the phone/fax numbers seems a bit strange to me. Of course, you can easily find their phone number from phone book.
JOhnny
Here's the local phone number for their sale dept in HKG:-
Farnell-Newark InOne Sales:
Sales Hotline Tel : (852) 22689888
Sales Hotline Fax : (852) 22689899
Sales email : hk-sales@farnell-newarkinone.com
Farnell-Newark InOne Sales:
Sales Hotline Tel : (852) 22689888
Sales Hotline Fax : (852) 22689899
Sales email : hk-sales@farnell-newarkinone.com
Hammond transformer
Hi CK,
You may check Hammond's web site to choose their power transfomer, and choke as well. They are very good too.
My friend and myself built several 2A3 power amplifer with Hammond's irons. We found them they are with very good quality.
If you need some help in picking the type of power transformer and choke, please let me know.
Johnny
Hi CK,
You may check Hammond's web site to choose their power transfomer, and choke as well. They are very good too.
My friend and myself built several 2A3 power amplifer with Hammond's irons. We found them they are with very good quality.
If you need some help in picking the type of power transformer and choke, please let me know.
Johnny
Thank you so much your help.
I can't find the product from HK Farnell.
But I will check the price to theml. I know some of their stuffs pricing is double to my seeing at MonKok Maks. I have their products catalog, so this OPT I can compare with the price to the other reseller of US . Like a mouser or Digi-Key ...
Power transformer I already have one bought from Taiwan's my3c.net , the model is T330 follow the link look at this "http://www.my3c.net/product/detail.asp?gid=0&ky=t330&pid=1691"
Are you sure I should deploy a Chock ? I have seen some of designs without it and instead to use solid state acting on it. I want to know two kind of difference based on sound level reproduction.
You say 2A3 , is it a substitution of 300B ?
CK
I can't find the product from HK Farnell.
But I will check the price to theml. I know some of their stuffs pricing is double to my seeing at MonKok Maks. I have their products catalog, so this OPT I can compare with the price to the other reseller of US . Like a mouser or Digi-Key ...
Power transformer I already have one bought from Taiwan's my3c.net , the model is T330 follow the link look at this "http://www.my3c.net/product/detail.asp?gid=0&ky=t330&pid=1691"
Are you sure I should deploy a Chock ? I have seen some of designs without it and instead to use solid state acting on it. I want to know two kind of difference based on sound level reproduction.
You say 2A3 , is it a substitution of 300B ?
CK
Hi Tang,
Farnell they replied the price for this unit is HKD980 including delivery charge.
But they told me this product lead time to deliver will more than 10 weeks.
CK
Farnell they replied the price for this unit is HKD980 including delivery charge.
But they told me this product lead time to deliver will more than 10 weeks.
CK
This is about right for the price and delivery lead time.
They don't have the OPT's in stock. They have to order them directly from Hammond and shipped from Canada or USA.
Well, 10 weeks isn't too long. Make up your mind. It's better to order the power transformer and choke as well.
Johnny
They don't have the OPT's in stock. They have to order them directly from Hammond and shipped from Canada or USA.
Well, 10 weeks isn't too long. Make up your mind. It's better to order the power transformer and choke as well.
Johnny
Chinese made OPT
Check at VT4C's web site. They offer various output transfomer. I don't know the quality but the price is very attractive:-
http://www.vt4c.com/shop/program/main.php?cat_id=30&group_id=7&hit_cat=
LM-9911U
3.5k output transformer designed for 845/300B SE.
3.5k Single Ended Output for 300B or low votlage 845
Max 120mA
Large 150W core enough 40W Class A power output
Made in China
Weight :2750 (gram/Each)
Size (mm): 92 x 82 x 99H
Power: 40 Watt
Item No: LM-9911U
Quantity (Each) Price (US$)
1 - 3 72.00
4 - 9 65.00
10 or more Call
Check at VT4C's web site. They offer various output transfomer. I don't know the quality but the price is very attractive:-
http://www.vt4c.com/shop/program/main.php?cat_id=30&group_id=7&hit_cat=
LM-9911U
3.5k output transformer designed for 845/300B SE.
3.5k Single Ended Output for 300B or low votlage 845
Max 120mA
Large 150W core enough 40W Class A power output
Made in China
Weight :2750 (gram/Each)
Size (mm): 92 x 82 x 99H
Power: 40 Watt
Item No: LM-9911U
Quantity (Each) Price (US$)
1 - 3 72.00
4 - 9 65.00
10 or more Call
47K of 12AT7's Grid resistor is a wrong value because it makes to the resultant loading resistor of the previous stage (12AX7) to become around 47K, which is an unacceptable loading (even lower than the plate resistance of 12AX7). You may get an unsymmetrical sine wave or very hign distortion.
470K is a reasonable value.
470K is a reasonable value.
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