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https://github.com/mdouchement/ampeg-heritage-b-15
Custom Ampeg Heritage B-15 schematic
https://github.com/mdouchement/ampeg-heritage-b-15
ampeg amplifier b-15 hb-15 heritage schematic tube valve vintage
Last synced: 11 days ago
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Custom Ampeg Heritage B-15 schematic
- Host: GitHub
- URL: https://github.com/mdouchement/ampeg-heritage-b-15
- Owner: mdouchement
- Created: 2021-11-11T19:10:20.000Z (about 3 years ago)
- Default Branch: main
- Last Pushed: 2022-08-27T17:43:42.000Z (over 2 years ago)
- Last Synced: 2024-11-10T09:32:12.100Z (2 months ago)
- Topics: ampeg, amplifier, b-15, hb-15, heritage, schematic, tube, valve, vintage
- Language: Go
- Homepage:
- Size: 19.5 MB
- Stars: 3
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# Ampeg HB15
This project is a custom modification of the original Ampeg Heritage B15.
You can download the schematic [HB15.pdf](HB15.pdf).
## Warnings
- Use **6L6GC** valves that support 500V at the screen
- Always checks that all capacitors are discharged
- Even if the 470k 2W resistor shoud discharged the capacitor
## Valves
Valves used in this project:
- TAD - 6L6GCM-STR REDBASE
- Philips USA as JAN 12AT7WC (6201) [NOS military grade]
- JAN 6SL7WGT Philips [NOS military grade]
- Shuguang 6N9P J level [NOS military grade]
## Custom mods
- The 100K 2W resistor in parallel with the standby switch reduce all the inrush current which is better for the capacitors
- Boost switches increase the gain of the triode by adding a bypass capactor
- Enable or disable the bright capacitor (boost in 8kHz)
- Effects Loop (buffered) is built to be transparent and you can do severals things around:
- Enable or disable the effects loop
- Can be used as a buffered preamp out
- Can be used as an input for a "preamp in a box"
- Can be used as distortion stage on the cathode follower by increasing the send volume
- *Eventually a clean boost of the preamp*
- Post Phase Inverter Master Volume (PPIMV) allowing to push the preamp while keeping the amplifier not too loud
- Negative Feedback loop for rumble fix and different voicing (see schematic)
- Midranges boost is a custom version inpired from Pignose B100V amp
- Adding a 4.7nF capacitor in series with C1 and C3 to cut sub frequencies
- It may be a side effect by replacing all 22nF by 47nF in order to support a 5 strings bass
- It also due to the frequency response of my PF-210HE cabinet which have a greater low frequencies response
- 3.3nF may be better depending your cabinet (and taste)
## Tips
- Use a rubber seal inside the chassis to easily mount a APEM 644 for example
- Use teflon tape and rubber seal to insulate metalic jack plug (e.g. Switchcraft 11) from the chassis to avoid ground loops
- Avoid soldering ground on the potentiometer's cover (gound loops enabler)
## Tools
- [KiCAD](https://kicad.org)
- https://gitlab.com/kicad/code/kicad
- https://github.com/KiCad
- [DIYLC](http://diy-fever.com/software/diylc)
- https://github.com/bancika/diy-layout-creator
- [LiveSPICE](https://github.com/dsharlet/LiveSPICE)
- [Micro-Cap](http://www.spectrum-soft.com/index.shtm)
## Resources
- https://ampeg.com/support/files/Schematics/
- http://www.valvewizard.co.uk/index.html
- https://www.ampbooks.com/mobile/amplifier-calculators
- http://www.guitarscience.net/tsc/info.htm (tonestack calculator)
- https://trioda.com/tools/triode.html (Loadline calculator)