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About shipping
1.Important: Import duties, taxes and other customs related charges all are not included into shipping cost . Buyers bear all responsibility for all extra charges incurred (if any).
2. We only ship to confirmed order addresses. Your order address MUST MATCH your Shipping address. We can ship to virtually any address in the world. Note that there are restrictions on some products, and some products cannot be shipped to international destinations.
3. When you place an order, we will estimate shipping and delivery dates for you based on the availability of your items and the shipping options you choose. Depending on the shipping provider you choose, shipping date estimates may appear on the shipping quotes page.
4.Please also note that the shipping rates for many items we sell are weight-based. The weight of any such item can be found on its detail page. To reflect the policies of the shipping companies we use, all weights will be rounded up to the next full pound. The shipping rate can be showed at the Checkout page. There are two options for shippig as below.
A. Standard Shipping(≤2KG): The Post Registered Air Mail, USPS/ePacket, PostNL, Singapore Post, or DHL Global Mail
B. Express Shipping: EMS, DHL, UPS , or Fedex, Special Route.,etc. For faster shipping and smooth transaction, we will change the shipping company among them
C. Economy Shipping: China Air Post Mail / Parcel, Hongkong Air Post Mail / Parcel, or shipment by sea etc
RETURNS POLICY
You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).
You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days). If you need to return an item, simply login to your account, view the order using the 'Complete Orders' link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.
SELLER GUARANTEES
1. One year Manufacturer`s limited Warranty for defective items (excluding items damaged and/or misused after receipt). Accessories come with a 3-month warranty.
2. Defective items MUST BE reported and returned within the warranty period (with the original packaging, if possible). You must tell us what the defect is and give us your order number. WE DO NOT REPAIR OR REPLACE ITEMS WITH AN EXPIRED WARRANTY. You agree to all of the above-listed policies upon ordering on our store.
SHIPPING RATE
How to check the latest shipping cost, please follow steps below.
1. Click the ADD TO CART button;
2. Click the GO TO CART button;
3. Input your Country, State or Province, Postal/Zip Code;
4. Finally, click the CALCULATE SHIPPING
Standard Shipping(≤2KG) ---Through Post Registered Air Mail, ePacket or DHL Global Mail,.etc.
| Weight(KG) | Shipping Code | Shipping Cost(USD) |
| 0.1~0.2 |
Standard Shipping The Post 0.2
|
3 |
| 0.21~0.3 |
Standard Shipping The Post 0.3
|
4 |
| 0.31~0.4 | Standard Shipping The Post 0.4 | 5 |
| 0.41~0.5 | Standard Shipping The Post 0.5 | 7 |
| 0.51~0.6 | Standard Shipping The Post 0.6 | 8 |
| 0.61~0.7 | Standard Shipping The Post 0.7 | 11 |
| 0.71~0.8 | Standard Shipping The Post 0.8 | 13 |
| 0.81~0.9 | Standard Shipping The Post 0.9 | 15 |
| 0.91~1.0 | Standard Shipping The Post 1.0 | 17 |
| 1.01~1.0 | Standard Shipping The Post 1.1 | 19 |
| 1.11~1.2 | Standard Shipping The Post 1.2 | 20 |
| 1.21~1.3 | Standard Shipping The Post 1.3 | 21 |
| 1.31~1.4 | Standard Shipping The Post 1.4 | 22 |
| 1.41~1.5 | Standard Shipping The Post 1.5 | 23 |
| 1.51~1.6 | Standard Shipping The Post 1.6 | 24 |
| 1.61~1.7 | Standard Shipping The Post 1.7 | 25 |
| 1.71~1.8 | Standard Shipping The Post 1.8 | 26 |
| 1.81~1.9 | Standard Shipping The Post 1.9 | 27 |
| 1.91~2.0 | Standard Shipping The Post 0.8 | 28 |
Express Shipping ---Through Special Routes, EMS, DHL, UPS ,Fedex, or TNT. For faster shipping and smooth transaction, we will change the shipping company among them
| Weight(KG) | Shipping Code | Shipping Cost(USD) |
| 0~0.5 |
Express Shipping L0.5
|
17 |
| 0.51~1 |
Express Shipping L1.0
|
20 |
| 1.01~1.5 | Express Shipping L1.5 | 25 |
| 1.51~2 | Express Shipping L2.0 | 30 |
| 2.01~2.5 | Express Shipping L2.5 | 35 |
| 2.51~3 | Express Shipping L3.0 | 38 |
| 3.01~3.5 | Express Shipping L3.5 | 40 |
| 3.51~4 | Express Shipping L4.0 | 42 |
| 4.01~4.5 | ExpressShipping L4.5 | 44 |
| 4.51~5 | Express Shipping L5.0 | 47 |
| 5.01~5.5 | Express Shipping L5.5 | 59 |
| 5.51~6 | Express Shipping L6.0 | 62 |
| 6.01~6.5 | Express Shipping L6.5 | 65 |
| 6.51~7 | Express Shipping L7.0 | 68 |
| 7.01~7.5 | Express Shipping L7.5 | 71 |
| 7.51~8 | Express Shipping L8.0 | 74 |
| 8.01~8.5 | Express Shipping L8.5 | 77 |
| 8.51~9 | Express Shipping L9.0 | 80 |
| 9.01~9.5 | Express Shipping L9.5 | 82 |
| 9.51~10 | Express Shipping L10.0 | 86 |
| 10.01~10.5 | Express Shipping L10.5 | 103 |
| 10.51~11 | Express Shipping L11.0 | 107 |
| 11.01~11.5 | Express Shipping L11.5 | 110 |
| 11.51~12 | Express Shipping L12.0 | 114 |
| 12.01~12.5 | Express Shipping L12.5 | 118 |
| 12.51~13 | Express Shipping L13.0 | 122 |
| 13.01~13.5 | Express Shipping L13.5 | 126 |
| 13.51~14 | Express Shipping L14.0 | 130 |
| 14.01~14.5 | Express Shipping L14.5 | 134 |
| 14.51~15 | Express Shipping L15.0 | 137 |
| 15.01~15.5 | Express Shipping L15.5 | 140 |
| 15.51~16 | Express Shipping L16.0 | 143 |
| 16.01~16.5 | Express Shipping L16.5 | 146 |
| 16.51~17 | Express Shipping L17.0 | 149 |
| 17.01~17.50 | Express Shipping L17.5 | 152 |
| 17.51~18 | Express Shipping L18.0 | 155 |
| 18.01~18.50 | Express Shipping L18.5 | 158 |
| 18.51~19 | Express Shipping L19.0 | 161 |
| 19.01~19.5 | Express Shipping L19.5 | 164 |
| 19.51~20 | Express Shipping L20.0 | 167 |
| 20.01~20.5 | Express Shipping L20.5 | 170 |
| 20.51~21 | Express Shipping L21.0 | 173 |
| 21.01~21.5 | Express Shipping L21.5 | 176 |
| 21.51~22 | Express Shipping L22.0 | 179 |
| 22.01~22.5 | Express Shipping L22.5 | 182 |
| 22.51~23 | Express Shipping L23.0 | 185 |
| 23.01~23.5 | Express Shipping L23.5 | 189 |
| 23.51~24 | Express Shipping L24.0 | 192 |
| 24.01~24.50 | Express Shipping L24.5 | 195 |
| 24.51~25 | Express Shipping L25.0 | 198 |
Note:
1.This table of shipping rate will be added to the checkout. The shipping rate can be showed at the Checkout page. And, the table is for reference only. Final shipping rate is subject to actual checkout.
2.The shipping rates for many items we sell are weight-based. The weight of any such item can be found on its detail page. To reflect the policies of the shipping companies we use, all weights will be rounded up to the next full pound.
3.If you have any questions about the shipping rate, pleas don't be hesitate to contact us through the ways as below.
Email: sales@iwistao.com
Description
Shuguang 274B Rectifier Tube 1 Piece Full-Wave High Vacuum 5V for 300B 2A3 Tube Amplifier HIFI Audio DIY
Model No: SG-274B
The Shuguang 274B is a high-performance, directly heated full-wave rectifier tube designed for high-voltage power supplies in tube amplifiers and other vacuum-tube audio equipment. Manufactured by Shuguang, it combines high-vacuum construction, carefully processed electrodes, and robust internal structure for stable and reliable rectification.
A special cathode treatment is used to provide a smooth, durable emitting surface with strong electron emission. During production, the tube undergoes an extended evacuation process using high-vacuum equipment to achieve a high degree of internal vacuum. The tube is also subjected to high-voltage conditioning, helping improve stability and reliability when operating under elevated B+ voltages.
Features
- High-vacuum construction for stable high-voltage operation
- Special electrode processing for strong and consistent electron emission
- High-voltage conditioning improves long-term stability
- Peak inverse voltage: over 850V
- DC output current: over 150mA
- Full-wave rectification for vacuum-tube amplifier power supplies
- Designed to minimize arcing under normal high-voltage operating conditions
- Suitable for many 274B / 5U4G-type rectifier applications
- Ideal for 300B, 2A3, 45 and other tube amplifier power supplies, subject to circuit requirements
Typical Specifications
| Parameter | Specification |
|---|---|
| Tube Type | 274B |
| Function | Full-Wave Rectifier |
| Construction | Directly Heated |
| Heater Voltage | 5V |
| Heater Current | Approx. 2A* |
| Peak Inverse Voltage | ≥ 850V |
| DC Output Current | ≥ 150mA |
| Base | Octal |
| Manufacturer | Shuguang |
| Application | Tube Amplifier High-Voltage Power Supply |
*The image supplied does not state the heater current; 5V/2A is the conventional 274B specification and should be confirmed against the manufacturer's datasheet for this exact production version.
274B and 5U4G Compatibility
The Shuguang 274B is commonly used in applications where a 5U4G-style octal rectifier is specified. However, rectifier tubes should not be treated as universally interchangeable simply because their bases and pin connections are similar.
Before replacing a 5U4G, 5AR4/GZ34, 5R4 or another rectifier with the 274B, verify the amplifier's heater supply, transformer voltage, DC current requirement, first filter capacitor value and resulting B+ voltage.
Ideal for Tube Amplifier Power Supplies
With its classic directly heated rectifier architecture and high-voltage capability, the Shuguang 274B is particularly well suited to traditional tube amplifier power supplies. It can be used in DIY and replacement applications for 300B SET amplifiers, 2A3 amplifiers, tube preamplifiers and other high-voltage vacuum-tube circuits where the electrical requirements are compatible.
For builders seeking a traditional full-wave vacuum rectifier with strong high-voltage capability and the characteristic behavior of a directly heated rectifier, the Shuguang 274B is a practical choice for both new builds and restoration projects.