Vacuum Tube Preamplifier Switching Power Supply Transformer AC 100-265V to 6.3V 5A 300V 300mA for 6P3P EL34 6P1 6P14 6V6 6P6P FU-7
Quick take
This AC 100-265V to vacuum-tube power transformer module is designed to feed two separate rails for tube builds: a 6.3V filament supply rated up to 5A and a high-voltage output around the 300V class. It tends to work well for smaller tube preamps and low-watt projects where you want practical, compact power with low reported noise, but the high-voltage rail can behave differently under certain loads and you should plan careful mounting and cooling.
Pros and cons
Pros
- Supports separate filament (6.3V, 5A) and high-voltage (about 300V, 300mA class) outputs for tube circuits.
- Buyers commonly report little to no added noise on filament and high-tension supplies in small tube amp setups.
- Wide AC input range (100-265V) makes it easier to integrate into different mains regions.
Cons
- High-voltage behavior under load may not match the top-end expectation immediately, and some setups report output issues.
- It needs proper chassis mounting and ventilation, especially as your project power rises.
- Best suited to small-to-medium tube builds, not a one-size-fits-all replacement for every high-current or mission-critical design.
What buyers think
Buyer-review evidence is limited but directionally consistent on a few points. Several users describe it as handy and effective for small tube guitar amp and preamp projects, using common tubes in the 6V6 family and other compact builds. A recurring theme is low noise performance, with reports of no obvious noise on both the high-voltage and filament supplies during use.
On the other hand, review evidence also includes cases where the high-voltage output did not behave as expected (for example, output not reaching the intended level) and at least one report of thermal overload behavior during a test scenario. Overall, buyer feedback supports the idea that this is workable for small projects, but it also reinforces the importance of matching your tube load, wiring, and cooling to the module’s intended operating region.
Key specs that matter for tube builders
- AC input: 100 to 265V.
- Filament supply: 6.3V rated up to 5A.
- High-voltage supply: about 300V class output with a current rating in the 300mA range.
- Independent rails: filament and high-voltage are treated as separate outputs.
For most DIY tube amps, the practical question is whether your circuit’s filament current and B+ current demands are aligned with these ratings. If your project pulls more from the high-voltage rail than the module can comfortably sustain, expect voltage sag, delayed ramp behavior, or protective shutdown depending on the exact load and thermal conditions.
Tube compatibility and typical use cases
This power supply module is positioned for vacuum tube preamp and amplifier projects built around common tube families, including (as listed) medium-power single-ended setups and lower-power push-pull machines. The included guidance points toward tubes such as:
- Medium-power single-ended: FU-7, 6P3P, EL34 (and similar medium-power single-ended builds)
- Lower-power push-pull and smaller single-ended projects: 6P1, 6P14, 6V6, 6P6P, 6L6 (and similar low-power designs)
If you are building a compact preamp or a small guitar amp, this rail pairing is the big reason it can be a good fit. If you are designing a higher-power amp with heavier continuous B+ draw, you may need a different approach for headroom and cooling.
Noise performance and build integration
One of the most important practical concerns when switching supplies feed tube circuits is added hum or hiss. The available review themes lean positive here, with reports of no noticeable noise on the high-tension and filament supplies during small project use. That said, your results still depend on your grounding scheme, wiring layout, and how securely you mount and route the transformer and cables inside the chassis.
A specific integration tip that comes up in feedback is securing the unit firmly to the chassis. Plan for solid mechanical mounting and keep power wiring away from input signal paths as you would with any tube power supply build.
Cooling and thermal headroom
The module is compact, and that makes airflow and chassis design part of the “specs.” Guidance tied to higher power levels emphasizes that cooling should be increased as power consumption rises, and that enclosing it in a very small sealed space is not a great idea.
Review evidence includes at least one thermal overload type of experience during a test with a resistive load. That doesn’t automatically mean it will happen in your guitar amp or preamp load, but it is a reminder that “rated voltage” does not replace thermal management. If your build will run near the high end of B+ current continuously, prioritize chassis ventilation and heat-sinking where appropriate.
Pros and cons recap
When this makes the most sense
- You are building a small tube preamp or low-watt tube amp and want a compact way to generate filament voltage and B+ from a wide-range AC input.
- You care about minimizing additional noise and you are comfortable with careful grounding and wiring practices.
- Your tube circuit’s current draw is in line with the filament and high-voltage class ratings.
Who should be cautious (or consider alternatives)
- Your design is mission-critical, or you require the high-voltage rail to meet expectations instantly under every load condition.
- You plan to run high B+ power continuously in a poorly ventilated enclosure.
- Your application needs a different voltage/current envelope than a 6.3V 5A filament plus ~300V class B+ supply.
Verdict
This vacuum tube preamp switching power supply transformer is a practical option for DIYers targeting small-to-medium tube projects, especially when you need a 6.3V filament rail and a ~300V B+ rail without a huge power transformer footprint. The biggest buying caveats are real, based on review evidence: the high-voltage output can be finicky under certain load conditions, and thermal management matters. If you match it to a smaller tube load and build it with solid grounding and chassis ventilation, it has a strong chance of being an effective solution for tube guitar amps and preamps.
FAQs
What voltages does this power supply provide?
It’s designed for an AC input of 100 to 265V and outputs two separate rails: 6.3V for the filament (rated up to 5A) and a high-voltage output in the 300V class (rated around 300mA).
Is it suitable for 6V6, EL34, or 6L6 tube builds?
It’s intended for tube amplifier and preamp projects using tube families listed for these kinds of circuits, including 6V6-class (low-power push-pull and small builds), EL34 (medium-power single-ended), and 6L6 (low-power builds). Your exact circuit current draw and operating points still determine compatibility.
Does it add noise to tube circuits?
Available buyer feedback generally reports low noise on both the filament and high-voltage supplies in small tube projects. Real-world results will depend heavily on your grounding, wiring layout, and how the unit is mounted in the chassis.
Will the high-voltage output always reach 300V immediately?
Review evidence includes cases where the high-voltage output behavior did not match expectations under certain test conditions or loads, and at least one report of thermal overload behavior. If you need precise high-voltage performance instantly under load, you should plan to test with your actual circuit conditions and ensure adequate cooling.
Does it need special cooling or a large chassis?
The module is relatively compact, so ventilation matters as power needs increase. For higher power draw, guidance emphasizes improving heat dissipation and avoiding very small sealed enclosures.
Specifications
| Product Title | Vacuum Tube Preamplifier Switching Power Supply Transformer AC 100-265V to 6.3V 5A 300V 300mA for 6P3P EL34 6P1 6P14 6V6 6P6P FU-7 |
|---|---|
| Category | Electronics > Power Accessories > Isolation Transformers |
| Brand | GODIYMODULES |
| Manufacturer | GODIYMODULES |
| Brand Name | GODIYMODULES |
| Part Number | LS165W-2T-01 |
| Included Components | 1PCS |
| Number of Items | 1 |
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